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MARYLAND  GEOLOGICAL  SURVEY 


DEVONIAN 

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MARYLAND 

ii 

GEOLOGICAL  SURVEY 


DEVONIAN 

PLATES 


SCIENCES 
UMAtf 


BALTIMORE,  MD.,  U.  S.  A. 


DEVONIAN 

LOWER 


270267 


NOTE 

Plates  I  to  XVI,  illustrating  the  Geological  and  Paleontological  Relations 
of  the  Lower  Devonian,  are  bound  with  the  text  volume.  The  following  plates 
illustrate  the  Systematic  Paleontology  of  the  Lower  Devonian  of  Maryland. 

All  drawings  cited  from  New  York  formations,  in  the  following  descriptions 
of  plates,  are  from  the  Paleontology  of  New  York,  and  are  after  Hall  or  Hall 
and  Clarke.  Only  in  cases  where  Hall  figured  material  from  Maryland  is 
acknowledgment  made  in  the  descriptions. 


PLATE  XVII 

PAGE 

Figs.  1-4.     HINDIA  SPH^ROIDALIS  Duncan 195 

1.  Exterior  view. 

2.  Radial  section  of  sponge. 

3.  Tangential  section  showing  tubes.     X  4. 

4.  Radial  section  showing  spicules  and  tubes.     X  4. 

Helderberg  formation,  Keyser  member,  Cash  Valley. 

Figs.  5-9.     STREPTELASMA  STKICTUM  Hall 198 

5.  6.  Lateral  and  posterior  views  of  corallum. 

7.  Transverse  section. 

New  Scotland  formation,  New  York. 

8.  Interior  of  calyx. 

9.  Transverse  section  of  corallum. 

Helderberg  formation,  New  Scotland  member,  Cherry  Run. 
W.  Va. 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,   PLATE  XVII 


CCELENTERATA — ANTHOZOA 


PLATE  XVIII 

PAGE 

Figs.  1,  2.     STREPTELASMA  CUMBEELANDICA  Swartz  n.  sp 199 

1.  Exterior  of  weathered  corallum. 

2.  Longitudinal  section  of  same  individual. 

Helderberg  formation,  near  Cumberland. 

Figs.  3-7.    ZAPHRENTIS  RCEMERI  M.  Edwards  and  Haime 200 

3.  Side  view  of  corallum,  questionably  referred  to  this  species.    Oris- 

kany  formation,  Ridgely  member,  Cumberland. 

4.  Side  view  of  corallum. 

5.  6.  Transverse  sections  of  corallum. 
7.  Longitudinal  section  of  corallum. 

New  Scotland  formation,  New  York. 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,   PLATE  XVIII 


CCELENTERATA — ANTHOZOA 


PLATE  XIX 

PAGE 

Figs.  1-4.     ZAPHRENTIS  KEYSERENSIS  Swartz  n.  sp 201 

1.  Side  view  of  type. 

2,  3.  Transverse  sections. 

4.  Longitudinal  section  of  a  small  individual. 

Helderberg  formation,  Keyser  member,  Keyser,  W.  Va. 

Pigs.  5-9.     CYATHOPHYLLUM  CLARKI  Swartz  n.  sp 201 

5.  Side  view  of  type. 

6.  Interior  of  calyx  of  same.    Martin  Mountain,  Allegany  County. 

7.  Transverse  section.    X  2.    Cumberland. 

8.  Longitudinal  section.    Martin  Mountain,  Allegany  County. 

9.  Side  view  of  corallum  showing  deep  annular  constrictions.     Same 

locality. 
Helderberg  formation,  Keyser  member. 

Figs.  10,  11.     CYATHOPHYLLUM  OHERNI  Swartz  n.  sp 203 

10.  Side  view  of  two  individuals.    The  corallum  on  right  side  is  in- 

complete. 

11.  Interior  of  calyx  of  one  of  preceding. 

Helderberg  formation,  Martin  Mountain,  Allegany  County. 

Figs.  12-17.     CYATHOPHYLLUM  RADICULUM  Rominger  ? 202 

12-14.  Side  views  of  three  coralla. 
15-17.  Calices  of  same  individuals. 

Helderberg  formation,  Keyser  member,  Cumberland. 


to 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,   PLATE  XIX 


f 


11 


13  14  15  16 

CCELENTERATA  —  ANTHOZOA 


17 


PLATE  XX 

PAGE 

Figs.  1-4.     CYATHOPHYLLUM  INEQUALE  (Hall) 205 

1.  Transverse  section  of  coralla. 

2,  3.  Portions  of  same.    X  2  and  X  5. 

4.  Longitudinal  section.    X  2. 

Helderberg  formation,  Keyser  member,  Flintstone. 

Figs.  5-9.     CYATHOPHYLLUM  SCHUCIIEBTI  Swartz  n.  sp 203 

5.  Cluster  of  branching  coralla.    Devil's  Backbone. 

6.  Single  stem.    Cash  Valley,  Lower  Stromatopora  bed. 

7.  Calyx.    Same  locality. 

8.  9.  Transverse  and  longitudinal  sections.    Devil's  Backbone. 

Helderberg  formation,  Keyser  member. 


n 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,   PLATE  XX 


CCELENTERATA — ANTHOZOA 


PLATE  XXI 

PAGE 

Figs.  1,  2.     CYATHOPHYLLUM  MARYLANDICUM  Swartz  n.  sp 204 

1.  Portion  of  a  branch.    Hyndman,  Pennsylvania. 

2.  View  of  calyx.    Cash  Valley,  Lower  Stromatopora  bed. 

Helderberg  formation,  Keyser  member. 

Figs.  3-6.     HEUOPHYLLTJM  CF.  COKNICULTJM  Lesueur 206 

3.  4.  Side  view  and  calyx.    Martin  Mountain,  Allegany  County. 

5,  6.  Small  individual,  questionably  referred  to  this  species.    Cumber- 
land. 

Helderberg  formation. 

Figs.  7-9.     CYSTIPHYLLUM  FASCICTJLATUM  Swartz  n.  sp 207 

7.  Side  view  of  several  corallites. 

8.  Transverse  section  of  same. 

9.  Transverse  section  of  a  single  corallite. 

Helderberg  formation,  Cumberland. 

Figs.  10,  11.     COLUMNARIA  ?  HELDERBERG  I.E  Swartz  n.  sp 207 

10.  Longitudinal  section  of  type. 

11.  Longitudinal  section  of  same.     X  5. 

Helderberg  formation,  Keyser  member,  Warrior  Mountain, 
Allegany  County. 


12 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,   PLATE  XXI 


CCELENTERATA — ANTHOZOA 


PLATE  XXII 

PAGE 

Fig.  1.     FAVOSITES   HELDERBERGI^E   Hall 208 

Corallum   showing  hemispherical   form.     New   Scotland   formation, 
New  York. 

Figs.  2-7.     FAVOSITES  HELDERBERGI.E  VAR.  PR^CEDENS  Schuchert 209 

2.  Corallum  of  lobate  form.    Keyser,  W.  Va. 

3.  Corallum  of  clavate  form.    Near  Seymour,  W.  Va. 

4.  Corallum  of  dendroid  form.    Keyser,  W.  Va. 

5, 6.  Tangential   and   radial   sections.      X  2%.     Lower    Stromatopora 

bed,  Devil's  Backbone. 

7.  Corallum  possessing  yery  small  cells.    Cash  Valley. 
Helderberg  formation,  Keyser  member. 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,  PLATE  XXII 


CCELENTERATA — ANTHOZOA 


PLATE  XXIII 

PA6E 

Figs.  1-4.     FAVOSITES  PYRIFORMIS  Hall 211 

1.  Transverse  section.     X  1. 

2.  Same.     X  2. 

3.  Longitudinal  section.     X  1. 

4.  Same.     X  2. 

Helderberg  formation,  Keyser  member,  Cumberland. 

Figs.  5-7.     FAVOSITES  CONICUS  Hall 212 

5.  6.  Side  view  and  base  of  characteristic  form. 

7.  Longitudinal  section  of  several  cells.    X  2. 

Helderberg  formation,  Becraft  member,  cut  of  B.  &  O.  R.  R. 
through  North  Mountain,  W.  Va. 

Figs.  8,  9.     FAVOSITES  BASALTICUS  Goldfuss 212 

8.  Portion  of  corallum. 

9.  Enlargement  of  several  cells.    X  2. 

Helderberg  formation,  Cumberland. 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,   PLATE  XXIII 


CCELENTERATA ANTHOZOA 


PLATE  XXIV 

PAGE 

Figs.  1,  2.     FAVOSITES  FAVOSUS  VAR.  INTEGRITABULATUS  Swartz  n.  var 214 

1.  Weathered  corallum. 

2.  Longitudinal  section  of  several  cells. 

Helderberg  formation,   Keyser  member,  Warrior  Mountain, 
Allegany  County. 

Figs.  3-6.     FAVOSITES  ?  SCHRIVERI  (Herzer) 214 

3.  4.  Upper  and  side  views  of  enlarged  base  of  corallum. 
5,  6.  Fragments  of  brandies. 

Oriskany  formation,  Ridgely  member,  opposite  Keyser,  W.  Va. 


15 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,   PLATE  XXIV 


CCELENTERATA — ANTHOZOA 


PLATE  XXV 

PAGE 
Figs.  1,  2.     STRIATOPORA  BELLA  Swartz  n.  sp 215 

1.  Portion  of  a  corallum. 

2.  Branching  corallum.     X  2. 

Helderberg  formation,  New  Scotland  member,  Cherry  Run, 
W.  Va. 

Fig.  3.     STBIATOPORA  sp 216 

Fragment   of  a  corallum.     Helderberg   formation,   Keyser   member, 
Devil's  Backbone. 

Figs.  4-7.     CLADOPOBA  RECTILINEATA  Simpson 216 

4.  Slab  covered  with  numerous  branches.    Keyser,  W.  Va. 

5.  A  branching  corallum.    Pinto. 

6.  Longitudinal  and  transverse  sections.     X  4.    Four  miles  northeast 

of  Cumberland. 

7.  Transverse  sections.    X  4.    Same  locality. 

Helderberg  formation,  Keyser  member. 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,   PLATE  XXV 


CCELENTERATA ANTHOZOA 


PLATE  XXVI 

PAGE 

Fig.  1.     PiEURODicTYUM  LENTICULARE  (Hall) 218 

Portion  of  a  corallum.    Helderberg  formation,  New  Scotland  member, 
near  Cumberland. 

Figs.  2,  3.     AULOPORA  SCHOHARI.E  Hall 219 

2.  Branching  corallum  attached  to  a  brachiopod. 

3.  Several  branches.     X  3. 

Helderberg  formation,  Becraft  member,  Ernstville. 

Figs.  4,  5.     AULOPORA  SCHUCHERTI  Swartz  n.  sp 219 

4.  View  of  type. 

5.  Enlargement  of  several  branches.    X  4. 

Helderberg  formation,  Keyser  member,  Cash  Valley. 

Figs.  6,  7.     CERATOPORA  ?  MARYLANDICA  Swartz  n.  sp 220 

6.  Slab  covered  with  numerous  branches. 

7.  Transverse  section  of  a  single  branch.     X  5. 

Helderberg  formation,  Keyser  member,  Keyser,  W.  Va. 

Fig.  8.     HALYSITES  CATENULATUS  Linne 220 

Corallum   showing  chain-like   branching.     Niagara   formation,   New 
York. 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,   PLATE  XXVI 


CCELENTERATA — ANTHOZOA 


PLATE  XXVII 

PAGE 

Figs.  1-6.     STROMATOPORA  CONSTELLATA  Hall 221 

1,  2.  Type  A.     Tangential  and  radial  sections.     X  10.    Lower  Stroma- 
topora  bed,  Devil's  Backbone. 

3.  Type  B.     Tangential  section.     X  10.    Keyser,  W.  Va. 

4.  Type  B.     Tangential  section.    X  10.    Cash  Valley. 

5.  6.  Type  C.     Tangential  and  radial  sections.     X  10.     East  bank  of 

Potomac  River  opposite  Pinto. 
Helderberg  formation,  Keyser  member. 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,   PLATE  XXVII 


' 

• 


,.  a  <,.• 

' 


•"• 

> 

'' 


"'  ' 


CCELENTERATA HYDROZOA 


PLATE  XXVIII 

PAGE 

Figs.  1,  2.     STROMATOPORA  CONSTELLATA  Hall 221 

Type  C.  Tangential  and  radial  sections  (thin  sections).  Showing 
very  large  and  intricately  branched  astorhizae.  Helderberg 
formation,  Keyser  member,  Cumberland. 

Figs.  3,  4.     SYRINGOSTROMA  BARRETTI  Girty 224 

3.  Section  obliquely  tangential.    X  10. 

4.  Section  obliquely  radial.     X  10.    Branch  of  Cladopora  rectilineata 

(Simpson)  at  edge. 

Helderberg  formation,  Keyser  member,  Cookerly,  Stromato- 
pora  bed. 

Figs.  5,  6.     SYRINGOSTROMA  CENTROTUM  Girty 225 

5.  6.  Tangential  and  radial  sections.     X  10.     Helderberg  formation, 

base  of  Keyser  member,  Warrior  Mountain,  Allegany  County. 


19 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,   PLATE  XXVIII 


m 


" 


5  6 

CGELENTERATA — HYDROZOA 


PLATE  XXIX 

PAGE 

Fig.  1.     STROMATOPORA  CONSTELLATA  Hall 221 

Type  A.    Portion  of  a  reef  formed  of  this  species.     X  %.    Helderberg 
formation,  Keyser  member,  Cumberland. 


20 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,  PLATE  XXIX 


CCELENTERATA HYDROZOA 


PLATE  XXX 

PAGE 

Fig.  1.     STROMATOPORA  CONSTELLATA  Hall 221 

Type  C.  View  of  surface  showing  mamelons  and  astorhizae.  Helder- 
berg  formation,  Keyser  member,  Devil's  Backbone,  Stromato- 
pora  bed. 

Fig.  2.     SYRIXGOSTROMA  CENTRQTUM  Girty 225 

View  of  surface  showing  numerous  small  mamelons.  Helder- 
berg  formation,  Keyser  member,  Warrior  Mountain,  Allegany 
County. 


•21 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,  PLATE  XXX 


CCELENTERATA — HYDROZOA 


PLATE  XXXI 

PAGK 

Figs.  1-5.     CAMAROCRINUS  STELLATUS  Hall 227 

1-3.  Three  transverse  cuts  through  the  same  bulb;  the  letters  indicate 
the  same  wall  in  the  different  sections;  M,  the  medio-basal 
chamber.  X  %. 

4.  Another  specimen  cut  through  the  center  longitudinally;  M,  medio- 

basal  chamber.     X  %. 

5.  A  second  bulb  cut  through  the  center  longitudinally.     X  %. 

Helderberg  formation,  Keyser  member,  Keyser,  W.  Va. 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,   PLATE  XXXI 


ECHINODERMATA — CYSTOIDEA 


PLATE  XXXII 

PAGE 

Figs.  1-3.     ANOMALOCYSTITES  ?  DISPARILIS  Hall 228 

1.  Anteal  or  concave  side,  showing  the  deeply  arched  or  crescentic 

form  of  base  with  the  succeeding  plates. 

2.  Posteal  or  convex  side,  showing  the  form  and  arrangement  of  plates. 

3.  Lateral  view  of  the  same  specimen. 

Oriskany  formation,  Ridgely  member,  Cumberland. 

Figs.  4-7.     LEPOCRINITES  GEBHARM  Conrad 229 

4.  The  anterior  side,  showing  the  pectinated  rhombs  at  the  base. 

5.  The  posterior  side,  showing  the  ovarian  aperture  with  the  sur- 

rounding plates  removed. 

6.  The  left  side  of  the  same  specimen.    The  prominence  of  the  ovarian 

side  over  the  opposite  is  well  seen. 

7.  Base  of  column,  showing  slight  evidences  of  rings. 

Coeymans  formation,  New  York. 

Figs.  8,  9.     LEPOCRINITES    MANLIUS    Schuchert 231 

Two  views  of  type.      X  2.     Helderberg  formation,  Keyser  member, 
Keyser,  W.  Va. 

Figs.  10,  11.     TETRACYSTIS  CHRYSALIS  Schuchert 232 

10.  View  showing  upper  left-hand  pectinirhomb.     X  2. 

11.  Same  specimen  from  the  antanal  side.    X  2. 

Helderberg  formation,  Keyser  member,  Keyser,  W.  Va. 

Figs.  12-16.     J^KELOCYSTIS  HARTLEYI  Schuchert 233 

12.  View  of  type;  a  large  specimen.    Anal  opening  to  the  right.    X  2. 

13.  A  smaller  specimen  with  the  anal  opening  to  the  left.     X  2. 

14.  Camera-lucida  drawing  of  the  oral  end  to  show  the  arrangement 

of  the  ambulacral  plates,  the  ambulacralia  (somewhat  re- 
stored), brachiole  attachments,  and  the  plate  with  the  madre- 
porite;  the  latter  lies  in  the  depression  of  the  large  plate  on  the 
left  of  the  figure.  X  2. 

15.  The  anal  pyramid;  the  positions  of  the  bounding  plates,  7,  8,  13, 

14,  are  indicated.     X  8. 

16.  Plates  14  and  15,  with  the  discrete-pectinirhombs;  the  dichopores 

on  plate  14  are  deeply  situated  and  do  not  show  on  the  surface. 
X  8. 
Helderberg  formation,  Keyser  member,  Keyser,  W.  Va. 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,   PLATE  XXXII 


12 


ECHINODERMATA — CYSTOIDEA 


PLATE  XXXIII 

PAGE 

Figs.  1,  2.     J^KELOCYSTTS   PAPILLATUS    Schuchert 234 

1.  Anal  view.    X  2. 

2.  Antanal  view  of  the  type;  pectinirhomb  14-15  is  faintly  indicated 

on  the  left.     X  2. 

Helderberg  formation,  Keyser  member,  Keyser,  W.  Va. 

Figs.  3,  4.     .LEKELOCYSTIS  AVEIXANA  Schuchert 235 

3.  View  of  type,  with  the  anal  opening  to  the  left  and  pectinirhomb  of 

plates  14-15  to  the  right.    X  3. 

4.  Same  specimen  from  above,  showing  the  two  small  discrete-pectini- 

rhombs,  the  central  madreporite,  and  the  large  anal  opening. 
X  3. 
Helderberg  formation,  Keyser  member,  Keyser,  W.  Va. 

Figs.  5-9.     PSEUDOCRINITES  GORDONI  Schuchert 236 

5.  6.  Two  views  of  type,  a  specimen  somewhat  larger  than  usual. 

7.  Another  specimen. 

8.  A  smaller  but  adult  individual  of  the  rounder  variety. 

9.  An  elongate  individual,  somewhat  abnormal  in  having  the  ambu- 

lacra drawn  over  on  the  anal  side  more  than  is  usual. 
Helderberg  formation,  Keyser  member,  Keyser,  W.  Va. 

Figs.  10-12.     PSEUDOCRINITES  ABNORMALIS  Schuchert 238 

10.  View  of  the  sides   having  the  abnormal  position   of  the  lower 

pectinirhomb. 

11.  Opposite  side  of  the  same  specimen. 

12.  End  view  of  same. 

Helderberg  formation,  Keyser  member,  Keyser,  W.  Va. 

Figs.  13,  14.     PSEUDOCRINITES  STELLATUS  Schuchert 239 

Two   side  views   of  type.     Helderberg   formation,   Keyser  member, 
Keyser,  W.  Va. 

Figs.  15-18.     PSEUDOCRINITES  CI.ARKI  Schuchert 240 

15-17.  Three  views  of  type,  an  average  adult  individual. 
18.  A  very  large  specimen  of  this  species.     The  plates  around  the 
pectinirhomb  are  somewhat  broken. 
Helderberg  formation,  Keyser  member,  Keyser,  W.  Va. 


24 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,   PLATE  XXXIII 


17 


18 


ECHINODERMATA CYSTOIDEA 


PLATE  XXXIV 

PAGE 

Figs.  1,  2.     PSEUDOCRINITES  SUBQUADRATUS   Schuchert 237 

Two  views  of  type.     X  2.     Helderberg  formation,  Keyser  member, 
Devil's  Backbone. 

Pigs.  3,  4.     PSEUDOCRINITES  ELQNGATUS  Schuchert 241 

Two  views  of  the  type.    Helderberg  formation,  Keyser  member,  Martin 
Mountain,  Bedford  County,  Penna. 


Figs.  5-7.     PSEUDOCRINITES  PERDEWI  Schuchert 

5.  Side  view  of  a  young  specimen.    X  2. 

6,  7.  Two  views  of  type. 

Helderberg  formation,  Keyser  member,  Keyser,  W.  Va. 


242 


244 


Figs.  8-10.     TRIMEROCYSTIS  PECULJAKIS  Schuchert 

8.  View  of  type  from  anal  side. 
9, 10.  Same  specimen  from  side. 

Helderberg  formation,  Keyser  member,  Keyser,  W.  Va. 


Figs.  11,  12.     SPH^EROCYSTITES  MULTIFASCIATUS  Hall 245 

11.  A  large  specimen,  from  anal  side;  most  of  the  sculpturing  con- 

sists of  the  ambulacral  branches.    X  2. 

12.  The  same  individual  from  above.     X  2. 

Helderberg  formation,  Keyser  member,  Cash  Valley. 

Figs.  13,  14.     SPH^ROCYSTITES  GLOBULARIS   Schuchert 247 

The  type  seen  from  anal  side  and  above.    X  2.    Helderberg  formation, 
Keyser  member,  Keyser,  W.  Va. 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,   PLATE  XXXIV 


12 


ECHINODERMATA CYSTOIDEA 


PLATE  XXXV 

PAGE 

Figs.  1-4.     SPH^BOCYSTITES  MUI/TIFASCIATUS  Hall 245 

1.  The  two  circles  of  plates  composing  the  anal  pyramid;  the  numbers 

indicate  the  bounding  thecal  plates.    About  X  5. 

2.  Part  of  an  ambulacrum,  showing  one  row  of  ambulacral  plates,  the 

ambulacralia,  and  remnants  of  brachioles.    About  X  10. 

3.  An  incomplete  brachiole.    About  X  10. 

4.  Deltoid   23,   with   the  madreporite   and   hydropore   closed   by   its 

pyramid.    About  X  10. 

Figs.  5,  6.     SPH^EROCYSTTTES  GLOBUT..ARIS   Schuchert 247 

5.  The  anal  pyramid  and  the  bounding  thecal  plates  indicated  by 

numbers.    About  X  5. 

6. 'Part  of  an  ambulacrum,  showing  the  ambulacral  and  ambulacralia 
plates,  and  the  points  of  attachment  for  the  brachioles.  About 
X  5. 

Fig.  7.     PSEUDOCRINITES  STELLATUS  Schuchert 239 

Part  of  an  ambulacrum,  showing  one  row  of  ambulacral  plates,  the 
brachiole  facets,  and  the  ambulacralia  with  their  intermediate 
large  plates.  About  X  5. 

Figs.  8-10.     PSEUDOCRINITES  PERDEWI  Schuchert 242 

8.  Deltoid  23,  with  the  madreporite  and  the  small  hydropore;    the 

double  row  of  small  plates  and  the  ambulacralia.    About  X  5. 

9.  Portion  of  an  ambulacrum  in  a  young  specimen.    About  X  5. 

10.  Same  as  fig.  9;  seen  from  the  side  to  show  the  high  elevation  of 
ambulacralia.    About  X  5. 

Figs.  11-13.     PSEUDOCRINITES   GORDONI   Schuchert 236 

11.  Portion  of  an  ambulacrum.    About  X  5. 

12.  A  nearly  complete  brachiole.    About  X  5. 

13.  Deltoid  23  crowded  into  the  ambulacral  plates,  showing  the  madre- 

porite and  hydropore.    About  X  5. 

Fig.  14.     PSEUDOCRINITES  CLARKI  Schuchert 240 

Plate  13  on  the  left  and  the  incomplete  circle  of  7  small  plates  bounding 
the  anal  pyramid  of  7  pieces.  About  X  5. 

Figs.  15-16.     LEPOCRINITES  MANLIUS  Schuchert 231 

15.  An  ambulacrum  near  the  oral  opening.    About  X  5. 

16.  The  two  circles  of  pieces  composing  the  anal  pyramid.    About  X  5. 


M 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,   PLATE  XXXV 


ECHINODERMATA — CYSTOIDEA 


PLATE  XXXVI 

PAGE 

Fig.  1.     SPH^ROCYSTITES  GLOBULARIS  Schuchert 247 

The  entire  stalk,  terminating  in  the  roots  at  one  end,  and  at  the  other 
preserving  a  few  of  the  thecal  plates,  seen  from  the  interior. 
Helderberg  formation,  Keyser  member,  Devil's  Backbone. 

Fig.  2.     SPH^EROCYSTITES  GLOBULARIS  VAR.  OVALIS  Schuchert 248 

Specimen  seen  from  the  side.  X  2.  Helderberg  formation,  Keyser 
member,  Keyser,  W.  Va. 

Figs.  3-7.     THYSANOCRINUS  ETJGENIUS  Ohern,  n.  sp 249 

3,  4.  Side  and  inferior  view  of  calyx. 

5.  Side  view  of  calyx  showing  bases  of  arms. 

6.  Exterior  view  of  an  arm. 

7.  Interior  view  of  bases  of  arms. 

Oriskany  formation,  Ridgely  member,  Cumberland. 

Figs.  8,  9.     TECHNOCRINUS  STRIATUS    (Hall) 250 

8.  Plate  belonging  to  this  species. 

9.  The  basal  plates  anchylosed  together  with  a  small  portion  of  the 

column  attached,  and  also  one  first  radial  plate. 

Oriskany  formation,  Ridgely  member,  Cumberland.     (After 
Hall.) 

Figs.  10,  11.     TECHNOCRINUS  SCULPTUS  Hall 250 

Basal  and  lateral  view  of  the  lower  part  of  the  body.  Oriskany  forma- 
tion, Ridgely  member,  Cumberland.  (After  Hall.) 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,   PLATE  XXXVI 


11 


10 


•••••••i" 

ECHINODERMATA — CYSTOIDEA — CRINOIDEA 


PLATE  XXXVII 

PAGE 

Figs.  1,  2.     TECHNOCBINUS  SPINULOSUS   (Hall) 251 

1.  The  body  and  bases  of  the  arms  with  a  portion  of  the  column 

attached. 

2.  Diagram  of  the  structure  of  the  body  to  the  base  of  the  arms,  as  far 

as  determined. 

Oriskany  formation,  Ridgely  member,  Cumberland.     (After 
Hall.) 

Figs.  3-5.     TECHNOCRINUS  ?  LEPIDTJS  Ohern  n.  sp 252 

3.  Inferior  view  of  calyx. 

4.  Cast  of  interior  of  calyx. 

5.  Side  view  of  interior  of  calyx. 

Oriskany  formation,  Ridgely  member,  near  Berkeley  Springs, 
W.  Va. 


28 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,   PLATE  XXXVII 


ECHINODERMATA — CRINOIDEA 


PLATE  XXXVIII 


Fig.  1.     TECHNOCRINUS  ?  LEPIDUS  Ohern  n.  sp 

Side  view  of  calyx  and  lower  part  of  arms. 
Ridgely  member,  near  Hancock. 


Oriskany  formation, 


PAGE 

.   252 


Fig.  2.     TECHNOCRINUS  ANDREWS:    (Hall) ' 251 

Side  view  of  calyx  and  base  of  arms.     Oriskany  formation,  Ridgely 
member,  Hancock. 


2!J 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER    DEVONIAN,   PLATE  XXXVIII 


ECHINODERMATA — CRINOIDEA 


PLATE  XXXIX 

Fig.  1.     TECHNOCRINUS  ?  LEPIDUS  Ohern  n.  sp 

Nearly  complete  specimen  showing  calyx  and  arms,     x  %.    Oriskany 
formation,  Ridgely  member,  Berkeley  Springs,  W.  Va. 


PAGE 
252 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,    PLATE  XXXIX 


ECHINODERMATA — CRINOIDEA 


PLATE  XL 

PAGE 

Figs.  1-3.     CALCEOCRINUS  MARYLANDICUS  Ohern  n.  sp 253 

Three  views  of  calyx  and  base  of  arms.    Oriskany  formation,  Ridgely 
member,  opposite  Keyser,  W.  Va. 

Figs.  4,  5.     HOMOCRINUS  PROBOSCIDALIS  Hall 255 

4.  View  of  calyx  and  base  of  arms. 

5.  Enlargement  of  same.     X  2. 

Oriskany  formation,  Ridgely  member,  Cumberland.     (After 
Hall.) 

Fig.  6.     HOMOCRINUS  HARTLEY:  Ohern  n.  sp 255 

Side  view  of  calyx.     Oriskany  formation,  Ridgely  member,  Cumber- 
land. 


Figs.  7-12.     EDRIOCRINUS  SACCULIIS  Hall 25G 

7-9.  Three  views  of  calyx  and  arms. 

10-12.  Three  views  of  calyx  and  arms  of  a  larger  specimen. 
Oriskany  formation,  Ridgely  member,  Cumberland. 

Figs.  13-15.     EDRIOCRINUS  POCILLIFORMIS  Hall 257 

13.  Basal  view  of  a  large  individual,  the  proportional  length  being 

greater  than  usual. 

14.  Lateral  view  of  the  same. 

15.  Interior  of  the  same. 

New  Scotland  formation,  New  York. 

Fig.  16.     CORNULITES  CINGUL.ATUS  Hall 258 

Small  specimen,  enlarged.    Helderberg  formation,  New  York. 


31 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,   PLATE  XL 


12 


ECHINODERMATA CRINOIDEA 


PLATE  XLI 

PAGE 
FigS.    1-5.       FlSTULIPORELLA  CUMULATA  U.  Sp 263 

1.  Side  view  of  a  zoarium,  natural  size. 

2.  Tangential  section.    X  20. 

3.  A   portion   of   the   same   tangential   section,    X  40,    showing   the 

characters  of  the  mature  zone. 

4.  Several  zooecia  of  the  same  section,    X  40,   from  a  less  mature 

portion. 

5.  Vertical  section,  X  20,  showing  several  layers  of  zoarium. 

Helderberg  formation,  Keyser  member,  Keyser,  W.  Va. 

FigS.    6-8.      FlSTtTLIPORELLA   QUINQUEDENTATA   n.    Sp 264 

6.  Tangential  section,  X  20,  of  the  type  specimen. 

7.  A  zocecium  of  the  same,  X  50,  showing  the  structure  of  the  lunarium. 

8.  Vertical  section  of  the  type,  X  20. 

Helderberg  formation,  Keyser  member,  Keyser,  W.  Va. 

Figs.  9-12.     CHILOTRYPA  MICROPORA  n.  sp 268 

9.  Zoarium,  natural  size,  with  end  view  of  same,  showing  sack-like 
form. 

10.  Tangential  section,   X  20,  exhibiting  the  very  small  zocecia  and 

the  rather  wide  interzooecial  spaces. 

11.  Vertical  section,  X  20,  through  portion  of  a  zoarium  illustrating 

the  variation  in  diameter  of  the  central  tube. 

12.  A  portion  of  the  same  vertical  section,   X  40,  showing  the  more 

minute  structure  of  the  zooecia  (zocec)  and  vesicles. 
Helderberg  formation,  Keyser  member,  Keyser,  W.  Va. 

Figs.  13-17.     CERAMOPORA  ?  IXCONDITA  n.  sp 260 

13.  A   tangential   section,    X  12,   passing  through   the   mature   zone 

where  the  zocecia  and  mesopores  are  most  irregular  in  shape 
and  arrangement. 

14.  A  similar  section,  X  12,  through  an  immature  portion  of  the  same 

zoarium. 

15.  A  vertical  section,  X  12,  through  both  zones  of  a  thin  incrusting 

zoarium  in  which  diaphragms  appear  to  be  wanting. 
16, 17.  Vertical  sections,   X  12,  showing  the  usual  characters  of  the 
mature  region. 
Helderberg  formation,  Keyser  member,  Devil's  Backbone. 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,   PLATE  XLI 


12  13 

MOLLUSCOIDEA — BRYOZOA 


«r  X\ 


PLATE  XLII 

PAGE 

Figs.  1-4.     STROMATOTRYPA  GLOBULARIS  n.  sp 279 

1,  2.  Two  vertical  sections,  X  10,  one  showing  the  usual  features  and 
the  second  illustrating  the  closing  of  a  mesopore  as  the  surface 
is  approached. 

3.  A  tangential  section,  X  20,  with  rounded  zocecia  and  rather  numer- 

ous acanthopores  and  mesopores. 

4.  A  few  zocecia,  X  20,  of  a  tangential  section  in  which  mesopores  are 

few. 
Helderberg  formation,  Keyser  member,  Keyser,  W.  Va. 

Figs.  5-9.     CYPHOTRYPA  CORRUGATA   (Weller) 269 

5.  Tangential  section,  X  20,  showing  the  simple  polygonal  zocecia. 

6.  7.  Several  zocecia  of  the  same  section,  X  50,  illustrating  the  minute 

structure  of  the  walls  and  acanthopores. 

8.  A  vertical  section  through  an  immature  and  mature  zone,  X  20. 

9.  Surface  of  a  zoarium,  X  9. 

Helderberg  formation,  Keyser  member,  Keyser,  W.  Va. 

Fig.  10.     PTILODICTYA  TENEIXA  n.  sp 288 

Tangential  section,  X  20,  illustrating  the  shape  of  the  zocecia  and 
showing  also  the  inferior  hemiseptum  as  a  sharp  transverse 
line  in  most  of  the  zocecia.  Helderberg  formation,  Keyser 
member,  Devil's  Backbone. 

Figs.  11-16.     STENOPORA  ?  INCRUSTANS  n.  sp 275 

11, 12.  Tangential  sections,    X  20,   showing  slight  variations   in  the 

wall  structure. 
13, 14.  Several  zocecia  in  thin  sections,  X  50,  illustrating  the  structure 

of  the  acanthopores  and  the  minute  dotting  of  the  walls. 

15.  Vertical  section,  X  20,  through  a  single  layer  of  zocecia. 

16.  Surface  of  a  specimen,  X  20. 

Helderberg  formation,  Keyser  member,  Cash  Valley. 


MARYLAND  GEOLOGICAL  SURVEY 

I       I 


LOWER   DEVONIAN,   PLATE  XLII 


MOLLUSCOIDEA — BRYOZOA 


PLATE  XLIII 

PAGE 

Figs.  1-4.     LJOCLEMA  SUBRAMOSUM  n.  sp 273 

1.  Vertical  section,  X  20. 

2,  3.  Tangential  section,  X  20,  through  the  mature  zone,  and  a  small 

portion  of  the  same,  X  50,  illustrating  the  structure  of  the  walls 
and  acanthopores. 

4.  A  tangential  section,  X  20,  through  an  early  stage  of  the  mature 

zone  where  the  acanthopores  are  undeveloped  and  the  zoo3cia 
are  thin  walled. 
Helderberg  formation,  Keyser  member,  Keyser,  W.  Va. 

Figs.  5-8.     ERIDOTRYPA  PARVULIPORA  n.  sp 272 

5.  A  tangential  section,  X  20. 

6.  A  portion  of  another  tangential  section,  X  20,  in  which  the  acantho- 

pores are  more  numerous. 

7.  Several  zocecia  of  a  thin  section,  X  50. 

8.  A  vertical  section,  X  20. 

Helderberg  formation,  Keyser  member,  Keyser,  W.  Va. 

Figs.  9-12.     LJOCLEMA  PULCHEIXUM,  n.  sp 274 

9, 10.  Tangential  section,  X  20,  and  a  portion,  X  35,  passing  through 
the  mature  zone. 

11.  A  vertical  section,  X  20. 

12.  Surface  of  the  type,  X  9. 

Helderberg  formation,  Keyser  member,  Keyser,  W.  Va. 

Figs.  13-16.     FiSTULiPORELLA  MINIMA  n.  sp 265 

13.  Side  view  of  a  zoarium,  natural  size. 

14.  Tangential  section,  X  20. 

15.  A  zooBcium  of  the  same  section,  X  50. 

16.  A  vertical  section,  X  20,  through  two  layers  of  zocpcia. 

Helderberg  formation,  Keyser  member,  Keyser,  W.  Va. 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,  PLATE  XLIII 


MOLLUSCOIDEA — BRYOZOA 


PLATE  XL  IV 

PAGE 

Figs.  1-3.     CEBAMOPORA  ?  INCONDITA  n.  sp 260 

1.  View  of  a  small  zoarium,  X  1.5,  incrusting  a  Favosites. 

2,  3.  Surface  of  same,  X  3  and  X  9,  respectively. 

Helderberg  formation,  Keyser  member,  Devil's  Backbone. 

Fig.  4.     CYPHOTBYPA  COBBUGATA   (Weller) 269 

Side  view  of  a  hemispheric  zoarium  with  the  edge  broken  away,  X  1.25. 
Helderberg  formation,  Keyser  member,  Pinto. 

Fig.  5.     LIOCLEMA  SUBBAMOSUM  n.  sp 273 

Fragment  of  a  zoarium,  X  1.5.    Helderberg  formation,  Keyser  mem- 
ber, Keyser,  W.  Va. 

Fig.  6.     STENOPOBA  ?  INCBUSTANS  n.  sp 275 

A  zoarium,  incrusting  a  specimen  of  Favosites,  X  1.25.     Helderberg 
formation,  Keyser  member,  Cash  Valley. 

Figs.  7-8.     ERIDOTBYPA  PABVULIPORA  n.  sp 272 

7.  Portion  of  small  slab,  X  1.25,  showing  several  fragments  of  this 

species. 

8.  Surface  of  one  of  the  specimens,  X  9. 

Helderberg  formation,  Keyser  member,  Keyser,  W.  Va. 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER  DEVONIAN,  PLATE  XLIV 


MOLLUSCOIDEA BRYOZOA 


PLATE  XLV 

PACK 

Figs.  1,  2.     BATOSTOMELLA  INTERPOROSA  n.  sp 270 

1.  Vertical  section,  X  20,  through  the  center  of  a  branch. 

2.  Tangential  section,  X  20,  showing  the  numerous  acanthopores  and 

mesopores. 

Helderberg   formation,   Keyser   member,    Devil's   Backbone, 
Maryland. 

Figs.  3-6.     DIPLOSTENOPORA  SILURIANA  (Weller) 277 

3.  Tangential    section,    X  20,    cutting   both    mature    and    immature 

region. 

4.  Portion  of  mature  region  of  the  same  section,  X  35. 

5.  Vertical  section,  X  20,  with  a  second  layer  of  zooecia  on  the  left. 

6.  One-half  of  the  same,    X  35,  illustrating  the  wall  structure  and 

perforated  diaphragms  in  more  detail. 
Helderberg  formation,  Keyser  member,  Devil's  Backbone. 

Fig.  7.     SEMICOSCINITJM  PLANUM  n.  sp 285 

Transverse  section  of  the  type  specimen,  X  12,  introduced  to  show  the 
expanded  carina.  Helderberg  formation,  Keyser  member, 
Hyndman,  Penna. 

FigS.    8-11.      FlSTULIPOREIXA  MARYLANDICA  n.  Sp 266 

8.  Portion  of  a  rather  narrow  zoarium,  natural  size. 

9.  Tangential  section,  X  20,  passing  through  a  macula  and  adjoining 

zooecia. 

10.  Several  zorecia  of  the  same  section,    X  35,   exhibiting  granular 

structure  of  lunarium. 

11.  Vertical  section,  X  20,  showing  a  portion  of  a  solid  branch. 

Helderberg  formation,  Keyser  member,  Cash  Valley. 

Figs.  12-14.     ORTHOPORA  RHOMBIFERA  Hall 286 

12.  Tangential    section,    X  20,    illustrating    quincuncial    arrangement 

and  rhomboidal  shape  of  zooscia  in  an  average  example. 

13.  Tangential  section  of  an  old  zoarium,  X  30. 

14.  Vertical  section,  X  20. 

Helderberg  formation,  Keyser  member,  Devil's  Backbone. 

Fig.  15.     FENESTELLA  (CYCLOPORINA)  ALTIDORSATA  n.  sp 282 

Transverse  section,  X  12,  showing  the  carinated  obverse  and  reverse 
sides  and  the  ovicell-like  structure  on  the  sides  of  the  carina. 
Helderberg  formation,  Keyser  member,  Devil's  Backbone. 


36 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,  PLATE  XLV 


f    10 

MOLLUSCOIDEA BRYOZOA 


11 


PLATE  XL VI 

PAGE 

Fig.  1.     RHOPALONARIA  ATTENUATA  Ulrich  and  Bassler 259 

The  excavations  left  by  a  portion  of  a  colony  upon  an  auloporoid,  X  9. 
Helderberg  formation,  Keyser  member,  Cash  Valley. 

Fig.  2.     ASCODICTYON  SILURIENSE  Vine 260 

Eight  groups  of  vesicles,  X  9,  attached  to  a  brachiopod.    Helderberg 
formation,  Keyser  member,  Cash  Valley. 

FigS.    3-7.       FlSTULIPORELLA   MAYNARDI  n.  Sp 266 

3.  A  slightly  oblique  tangential  section,  X  20,  illustrating  the  struc- 

ture of  the  outer  ridge-like  walls  on  one  edge  of  the  drawing 
and  the  usual  zocecia  and  mesopores  elsewhere. 

4.  Tangential    section,    X  20,    through    the    outermost    part    of   the 

zoarium. 

5.  Vertical  section,  X  20,  through  two  layers  of  zooacia  but  not  includ- 

ing the  outer  ridge-like  wall  in  either  layer. 

6.  Surface  view  of  zooecia,  X  9,  with  crested  walls  and  overarching 

lunaria  well  developed. 

7.  View  of  another  portion  of  the  same  specimen,  X  9,  in  which  the 

ridge-like  outer  wall  is  shown  only  in  one  corner. 
Helderberg  formation,  Keyser  member,  Cash  Valley. 

Figs.  8-9.     STROMATOTRYPA  GLOBULARIS  n.  sp 279 

8.  Side  view  of  a  zoarium,  natural  size,  showing  a  portion  of  the 

wrinkled  base. 

9.  Surface  of  zoarium,  X  9. 

Helderberg  formation,  Keyser  member,  Keyser,  W.  Va. 


37 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,   PLATE  XLVI 


MOLLUSCOIDEA BRYOZOA 


PLATE  XLVII 

PAGE 

Figs.  1,  2.     FENESTEIXA  CUMBERLANDICA  n.  sp 280 

1.  Obverse  face,  X  5. 

2.  Reverse  face,  X  5. 

Helderberg  formation,  Keyser  member,  Cash  Valley. 

Fig.  3.     POLYPORA  DICTYOTA  n.  sp 283 

Reverse  face  of  the  type  specimen,  X  5.    Helderberg  formation,  Keyser 
member,  Devil's  Backbone. 

Figs.  4-6.     THAMNISCUS  KEGULARIS  n.  sp 286 

4,  6.  Celluliferous  and  non-celluliferous  face  respectively  of  the  two 

type  specimens,  X  1.5. 
6.  Enlargement  of  a  portion  of  fig.  4,  X  5. 

Helderberg  formation,  Keyser  member,  Devil's  Backbone. 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,   PLATE  XLVII 


MOLLUSCOIDEA — BRYOZOA 


PLATE  XLVIII 

PAGE 

Figs.  1-3.     DIPLOSTENOPORA  siLURiANA  (Weller) 277 

1.  An  incomplete  zoarium  of  average  size,  X  1.5,  with  low  monticules. 

2.  A  more  robust  incomplete,  smooth  zoarium,  X  1.5. 

3.  Surface  of  specimen  shown  in  fig.  1,  X  9. 

Helderberg  formation,  Keyser  member,  Cash  Valley. 

Fig.    4.       FlSTULIPORELLA    MARYLANDICA   n.   Sp 266 

Surface  of  a  zoarium,  X  6,  exhibiting  the  well-marked  solid  maculae. 
Helderberg  formation,  Keyser  member,  Cash  Valley. 

Fig.  5.     BATOSTOMELLA  INTERPOROSA  n.  sp 270 

One   of   the    type    specimens,    X  5.      Helderberg    formation,    Keyser 
member,  Devil's  Backbone. 

Fig.  6.     ORTHOPORA  RHOMBIFERA  Hall 286 

Surface  of  a  slab,  X  5,  showing  numerous  fragments  of  this  species. 
Helderberg  formation,  Keyser  member,  Cash  Valley. 

Figs.  7,  8.     PTILODICTYA  TENELLA  n.  sp 288 

7.  Incomplete  specimen,  X  5. 

8.  Surface  of  same,  X  9. 

Helderberg  formation,  Keyser  member,  Devil's  Backbone. 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,   PLATE  XLVIII 


MOLLUSCOIDEA — BRYOZOA 


PLATE  XLIX 

PAGE 

Figs.  1-3.     FENESTELLA  (CYCLOPORINA)  ALTIDORSATA  n.  sp 282 

1.  An  incomplete,  well-preserved  frond,  X  1.5. 

2.  Surface  of  a  slab,  X  2,  with  specimens  showing  both  obverse  and 

reverse  sides. 

3.  A  third  specimen,  X  5,  exhibiting  the  celluliferous  face. 

Helderberg  formation,  Keyser  member,  Devil's  Backbone. 

Fig.  4.     SEMICOSCINIUM  PLAXUM  n.  sp 285 

Portion  of  the  non-celluliferous  face  of  the  type  specimen,  x  5.    Helder- 
berg formation,  Keyser  member,  Hyndman,  Penna. 


40 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,  PLATE  XLIX 


MOLLUSCOIDEA — BRYOZOA 


PLATE  L 

PAGE 

Figs.  1-4.     MONOTRYPA   TABTJLATA    (Hall) 278 

1.  Vertical  fracture  of  a  zoarium,  natural  size,  showing  corrugated 

zooecial  walls. 

2.  A  portion  of  the  same  enlarged. 

3-4.  Vertical  and  tangential  sections,  X  6. 

New  Scotland  formation,  New  York. 

Figs.  5-8.     CALLOTKYPA  STRIATA  (Hall  and  Simpson) 271 

5.  A  fragment  of  limestone  with  small  examples  of  this  species,  natural 

size. 

6,  7.  A  small  fragment  and  a  portion  of  the  same  enlarged. 

8.  A  further  enlargement   (X  18),  showing  the  arrangement  of  the 
zooacia  and  mesopores  and  the  prominent  spine,  at  the  posterior 
end  of  the  zooacium. 
New  Scotland  formation,  New  York. 

Figs.  9,  10.     CALLOTRYPA  MACROPORA    (Hall) 271 

A  branching  fragment  and  a  portion  of  the  same  enlarged.    New  Scot- 
land formation,  New  York. 

Figs.  11,  12.     ERIDOTRYPA  CORTICOSA  (Hall) 273 

A  fragment,  natural  size,  and  a  portion  of  the  same  enlarged  showing 
the  thick  walled  zocecia.    New  Scotland  formation,  New  York. 

Figs.  13-15.     CHILOTRYPA  CONSTRICTA   (Hall) 269 

13.  A  small  piece  of  limestone  with  fragments  of  this  species. 
14, 15.  Two  fragments  enlarged,  the  first  showing  the  regular  arrange- 
ment of  the  zooecia  and  the  second  showing  several  maculae. 
New  Scotland  formation,  New  York. 

Figs.  16-18.     ORTHOPORA  OVATIPORA   (Hall) 288 

16, 17.  A  fragment,  natural  size,  and  an  enlargement  of  the  same. 
18.  Surface  of  a  fragment,  X  18. 

New  Scotland  formation,  New  York. 


41 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,   PLATE  L 


MOLLUSCOIDEA — BRYOZOA 


PLATE  LI 

PAGE 

Figs.  1,  2.     FISTULIPORA  MACULOSA    (Hall) 262 

1.  A    complete    zoarium,    natural    size,    showing   the    characteristic 

maculae. 

2.  Surface  of  a  zoarium  magnified. 

New  Scotland  formation,  New  York. 

Figs.  3-5.     SEMICOSCINIUM  CORONIS   (Hall) 285 

3.  A  fragment,  natural  size. 

4.  An  enlargement  of  the  non-celluliferous  face. 

5.  Celluliferous  face  enlarged,  showing  the  characteristic,  expanded 

carina. 
New  Scotland  formation,  New  York. 

Figs.  6-8.     FENESTELLA  PHJLIA  Hall 281 

6, 7.  A   fragment   showing   the   non-celluliferous   face,    X  1,   and   an 
enlargement  of  the  same. 

8.  Enlargement  of  the  celluliferous  side. 

New  Scotland  formation,  New  York. 

Figs.  9-11.     POLYPORA  COMPACTA    ( Hall) 284 

9.  A  fragment,  natural  size. 

10, 11.  Enlargements  of  the  non-celluliferous  and  celluliferous  faces 
of  this  species. 
New  Scotland  formation,  New  York. 

Figs.  12-14.     STICTOPORA  ?  PAPILLOSA  Hall 289 

12.  Fragments,  natural  size. 

13-14.  Surface  of  specimen,  X  6  and  X  18. 

New  Scotland  formation,  New  York. 

Figs.  15-17.     ORTHOPORA  REGULARIS   (Hall) 287 

15.  A  specimen  showing  a  rectangular  mode  of  branching,  X  1. 
16, 17.  Surfaces   of  two  specimens,    X  6,   showing  variations   in  the 
thickness  of  the  zocecial  walls. 

New  Scotland  formation,  New  York. 

Fig.  18.     ORTHOPORA  RHOMBIFERA    (Hall) 286 

Enlargement  of  a  specimen  showing  arrangement  and  form  of  the 
zofficial  apertures.    New  Scotland  formation,  New  York. 


42 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,   PLATE  LI 


11 


10 


MOLLUSCOIDEA — BRYOZOA 


PLATE  LI  I 

PAGE 

Figs.  1,  2.     CYPHOTRYPA  CORRUGATA   (Weller) 269 

1.  Vertical  section,  showing  the  characteristic  crenulated  walls  and 

the  distribution  of  diaphragms.     X  20. 

2.  Tangential  section  illustrating  the  range  in  size  of  the  macular  and 

intermacular  zorecia.     X  20. 

Decker  Ferry  formation,  New  Jersey. 

Figs.  3,  4.     DIPLOSTEXOPORA  SILURIANA  (Weller) 277 

3.  A  vertical  section  illustrating  the  bifoliate  method  of  growth  and 

the  characteristic  perforated  diaphragms.     X  20. 

4.  Several  zocecial  tubes  of  the  same  section.     X  35. 

Decker  Ferry  formation,  New  Jersey. 

Figs.  5-8.     MONOTRYPA  SPH.ERICA  (Hall) 278 

5.  Side  view  of  a  zoarium,  natural  size. 

6.  A  vertical  fracture,  natural  size. 

7.  An  enlargement  of  the  celluliferous  surface. 

8.  Vertical  section  illustrating  the  distribution  of  the  diaphragms. 

X  4. 
New  Scotland  formation,  New  York. 

Figs.  9-11.     FENESTELLA  ?  IDALIA  Hall 281 

9.  A  funnel-shaped  frond,  natural  size. 

10.  An  enlargement  of  the  non-celluliferous  face  of  the  same. 

11.  An  enlargement  of  another  specimen  with  stouter  branches. 

New  Scotland  formation,  New  York. 


13 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,  PLATE  Lll 


Mm  lit  <iiif«; 

nil 


MOLLUSCOIDEA — BRYOZOA 


PLATE  LI  1 1 

PAGE 

Figs.  1,  2.     ORBICULOIDEA  BCEDERI  Schuchert  n.  sp 290 

1.  Exterior  of  dorsal  valve. 

2.  Exterior  mold  of  ventral  valve. 

Oriskany  formation,  Ridgely  member,  Cash  Valley. 

Figs.  3-5.     OBBICULOIDEA  AMPLA  (Hall) 291 

3.  Cast  from  a  mold  of  the  dorsal  valve. 

4.  Side  elevation  of  same. 

5.  Partially  exfoliated  ventral  valve. 

Oriskany  formation,  New  York. 

Figs.  6,  7.     ORBICULOIDEA  SCHUCHEBTI  Swartz  n.  sp 292 

6.  Exterior  of  dorsal  valve. 

7.  Exterior  of  ventral  valve. 

Helderberg  formation,  Keyser  member,  Dawson,  W.  Va. 

Figs.  8,  9.     PHOLIDOPS  MULTILAMELLOSA  Schuchert  n.  sp 293 

8.  Exterior  of  ventral  ?  valve  partially  exfoliated,  showing  interior 

muscular  scars.    X  2. 

9.  Exterior  of  dorsal  valve.     X  2. 

Oriskany  formation,  Shriver  member,  Cash  Valley. 

Figs.  10-12.     PHOLIDOPS  OVATA  Hall 294 

10.  Exterior  of  dorsal  valve.     X  3.    New  Scotland  of  New  York. 

11.  Interior  of  dorsal  valve.    X  5. 

12.  Exterior  of  dorsal  valve.     X  5. 

Helderberg  formation,  Keyser  member,  %  mile  southwest  of 
Rawlings. 

Fig.  13.     PHOLIDOPS  TUMIDA  Schuchert  n.  sp 294 

Exterior  of  dorsal  valve.     X  3.    Oriskany  formation,  Shriver  member, 
Winchester  road. 

Figs.  14-19.     LIXGULAPHOLIS  TERMINALIS  (Hall) 296 

14.  Exterior  of  ventral  valve. 

15.  Exterior  of  dorsal  valve. 

16.  Exterior  of  dorsal  ?  valve  of  another  specimen.    X  2. 

17.  Profile  outline  of  same,  showing  both  valves  in  position. 

18.  Interior  of  ventral  valve.    X  2. 

19.  Interior  of  ventral  valve.    X  3. 

Oriskany  formation,  Ridgely  member,  Cumberland.     (Figs. 
14,  15,  19,  after  Hall.) 

Figs.  20-23.     ORTHOSTROPHIA  STROPHOMENOIDES  (Hall) 297 

20.  21.  Internal  casts  of  ventral  and  dorsal  valves. 
22,  23.  Dorsal  and  cardinal  views. 

New  Scotland  formation,  New  York. 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER  DEVONIAN,  PLATE   Llll 


MOLLUSCOIDEA — BRACHIOPODA 


PLATE  LIV 

PAGE 

Figs.  1-6.     DALMANELLA  PLANICONVEXA   (Hall) 298 

I,  2.  Dorsal  and  ventral  shells.     X  11A.     Helderberg  formation,  New 

Scotland  member,  21st  Bridge. 

3.  Ventral  valve.    Helderberg  formation,  Becraft  member,  Cherry  Run, 

W.  Va. 

4.  The  interior  of  dorsal  valve  of  a  smaller  individual. 

5.  Interior  of  ventral  valve. 

6.  Cardinal  view  of  a  larger  individual.    New  Scotland  formation,  New 

York. 

Figs.  7-10.     DALMANELLA  CLARK i  Maynard  n.  sp 300 

7.  Interior  of  ventral  valve.    X  21/&. 

8.  Dorsal  valve.     X  2. 

9.  Ventral  valve.     X  2. 

10.  Interior  of  dorsal  valve.    X  2. 

Helderberg  formation,  Keyser  member,  Cash  Valley. 

Figs.  11-13.     DALMANELLA  CONCINNA    (Hall) 301 

II.  Ventral  valve. 

12.  Surface  ornamentation.    X  7. 

13.  Dorsal  valve. 

Helderberg  formation,  Keyser  member,  Cumberland. 

Figs.  14-23.     DALMANELLA  PERELEGANS  (Hall) 299 

14, 15.  Ventral  and  dorsal  valves.     Helderberg  formation,  New  Scot- 
land member,  Corriganville. 
16-19.  Ventral,  dorsal,  side,  and  cardinal  views. 

20.  Interior  of  ventral  valve. 

21.  Internal  cast  of  ventral  valve. 

22.  Internal  cast  of  dorsal  valve. 

23.  Interior  of  dorsal  valve. 

New  Scotland  formation,  New  York. 

Figs.  24-26.     DALMANELLA  EMINENS   (Hall) 299 

24.  Dorsal  view. 

25.  Profile  outline  of  same. 

26.  Interior  of  ventral  valve. 

Helderberg  formation,  New  Scotland  member,  Corriganville. 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,   PLATE  LIV 


12 


13 


14 


15 


'-''•^^^^^ 


10 


11 


21 


22 


25 


MOLLUSCOIDEA — BRACK  IOPODA 


PLATE  LV 

PAGE 

Figs.  1-8.     RHIPIDOMELLA  EMARGINATA  (Hall) 302 

1-4.  Illustrations  of  the  form  and  character  of  this  variety. 
5,  6.  Interior  of  ventral  and  dorsal  valves. 
7,  8.  Cast  of  the  ventral  and  dorsal  valve. 

Helderberg  formation,  Keyser  member,  Cumberland.     (After 
Hall.) 

Figs.  9-16.     RHIPIDOMELLA  OBLATA    (Hall) 303 

9, 10.  Ventral  and  dorsal  valves. 

11.  Profile  of  same. 

12.  A  small  dorsal  valve. 

13, 14.  Interior  of  ventral  and  dorsal  valves. 

15.  Internal  cast  of  the  ventral  valve,   showing  the  muscular  and 

vascular  impressions. 

16.  Cast  of  the  dorsal  valve,  with  impressions  of  the  cardinal  and 

brachial  processes. 

New  Scotland  formation,  New  York. 

Figs.  17-19.     RHIPIDOMELLA  ASSIMILIS   (Hall) 304 

17.  Ventral  valve. 

18.  Dorsal  view  of  a  large  shell. 

19.  Interior  of  ventral  valve. 

Helderberg  formation,  Becraft  member,  North  Mountain,  W. 
Va. 

Fig.  20.     RHIPIDOMELLA  MVSCULOSA  (Hall) 305 

Cast  of  interior  of  dorsal  valve.    Oriskany  formation,  New  York. 

Figs.  21,  22.     RHIPIDOMELLA  MUSCULOSA  VAR.  ARCTISIXUATA  Schuchert  n. 

var 306 

21.  Dorsal  view. 

22.  Ventral  view  of  same. 

Oriskany  formation,  Ridgely  member,  Cumberland. 

Fig.  23.     RHIPIDOMELLA  MARYLANDICA  Schuchert  n.  sp 306 

Interior  cast  of  ventral  valve.    Oriskany  formation,  Ridgely  member, 
Williams  road,  near  Cumberland. 


46 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER  DEVONIAN,  PLATE  LV 


21  22 

MOLLUSCOIDEA — BRACHIOPODA 


23 


PLATE  LVI 

PAGE 

Figs.  1-4.     RHIPIDOMELLA   MUSCULOSA    (Hall) 305 

1.  Exterior  of  dorsal  shell. 

2.  Lateral  view  of  the  conjoined  valves. 

3.  Interior  of  dorsal  valve. 

4.  Interior  of  ventral  valve. 

Oriskany  formation,  Ridgely  member,  Cumberland.     (After 
Hall.) 

Figs.  5-8.     SCHIZOPHORIA   MULTISTRIATA    (Hall) 307 

5.  6.  Dorsal  and  side  views  of  shells. 

7,  8.  Internal  cast  of  ventral  and  dorsal  valves. 
New  Scotland  formation,  New  York. 

Figs.  9-12.     SCHIZOPHORIA  ORISKANIA  Schuchert  n.  sp 307 

9, 10.  Dorsal  and  side  views.    The  discontinuous  striae  in  the  drawing 

are  due  to  the  pseudomorphous  nature  of  the  specimen. 
11, 12.  Internal  casts  of  ventral  and  dorsal  valves. 

Oriskany  formation,  Ridgely  member,  Cumberland. 

Figs.  13-17.     LEPT^NA  RHOMBOIDALIS    (Wilckens) 308 

13, 15.  Ventral  and  dorsal  views. 
14.  Ventral  valve. 

16.  Interior  of  dorsal  valve,  showing  some  variety  of  character. 

17.  Internal  cast  of  ventral  valve. 

New  Scotland  formation,  New  York. 

Fig.  18.     LEPT.ENA  RHOMPXHDAOS  VAR.  VEXTRICOSA  (Hall) 309 

Interior  view  of  dorsal  valve.    Oriskany  formation,  New  York. 


47 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,   PLATE  LVI 


MOLLUSCOIDEA — BRACHIOPODA 


PLATE  LVII 

PAGE 

Fig.  1.     LEPT^EXA  RHOMBOIDALIS  VAR.  VEXTRICOSA  (Hall) 309 

Interior  of  ventral  valve.  Oriskany  formation,  Ridgely  member, 
Cumberland.  (After  Hall.) 

Figs.  2-6.     LEPT^NISCA  CONCAVA   (Hall) 310 

2.  Ventral  exterior. 

3.  Dorsal  aspect. 

4.  Enlargement  of  the  surface,  showing  the  finer  longitudinal  striae. 

New  Scotland  formation,  New  York. 

5.  Exterior  of  ventral  valve.     X  2. 

Helderberg  formation,  New  Scotland  member,  Devil's  Back- 
bone. 

Fig.  6.     STROPHEODONTA  COEYMANENSIS  Swartz  n.  sp 313 

Ventral  valve  showing  exterior  save  in  center  where  muscular  scars 
of  interior  are  seen.  Helderberg  formation,  Coeymans  member, 
Devil's  Backbone. 

Figs.  7-10.     STROPHEODOXTA  ARATA   (Hall) 311 

7.  Side  view. 

8.  Ventral  valve  more  or  less  exfoliated. 

9.  The  surface  showing  ridges  and  striae. 

New  Scotland  formation,  New  York. 

10.  Small  ventral  valve.     Helderberg  formation,  Coeymans  member, 
Devil's  Backbone. 

Fig.  11.     STROPHEODOXTA  DEMISSA   (Conrad) 313 

Internal  cast  of  ventral  valve.  Oriskany  formation,  Ridgely  member, 
Pendleton  County,  W.  Va. 

Figs.  12,  13.     STROPHEODOXTA   (LEPTOSTROPHIA)   BECKII   (Hall) 314 

12.  Ventral  exterior. 

13.  Ventral  interior. 

New  Scotland  formation,  New  York. 

Figs.  14-16.     STROPHEODOXTA  (LEPTOSTROPHIA)  PLAXULATA  (Hall) 315 

14.  An  individual  showing  faint  concentric  undulations. 

15.  Ventral  valve  partially  exfoliated. 

Coeymans  formation,  New  York. 

16.  Ventral  valve  differing  from  usual  form. 

Helderberg    formation,    Becraft    member,    Licking    Creek, 
Penna. 

Figs.  17,  18.     STROPHEODOXTA  (LEPTOSTROPHIA)   BIPARTITA  (Hall) 316 

17.  Exterior  of  ventral  valve.    Pinto. 

18.  Interior  of  ventral  valve.    Devil's  Backbone. 

Helderberg  formation,  Keyser  member. 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,   PLATE  LVII 


18 


12 


MOLLUSCOIDEA — BRACHIOPODA 


PLATE  LVIII 

PAGE 

Fig.  1.     STROPHEODONTA  (LEPTOSTROPHIA)  ARCTIMUSCULA  Schuchert  n.  sp. .   317 
Interior  of  ventral  valve.    Oriskany  formation,  Shriver  member,  21st 
Bridge. 

Figs.  2-5.     STROPHEODONTA  (LEPTOSTROPHIA)  MAGNIFICA  (Hall) 318 

2.  Exterior  of  ventral  valve. 

3.  View  of  dorsal  valve. 

4.  Ventral  interior. 

5.  Interior  of  dorsal  valve. 

Oriskany  formation,  Ridgely  member,  Cumberland.     (Figs. 
3-5  after  Hall.) 

Figs.  6-8.     STROPHEODONTA  (LEPTOSTROPHIA)  MAGNIVENTRA  (Hall) 319 

6.  Internal  cast  of  ventral  valve.    Oriskany  formation,  New  York. 

7.  Interior  of  dorsal  valve. 

8.  Exterior  of  ventral  valve. 

Oriskany  formation,  Ridgely  member,  Cumberland.     (Fig.  6 
after  Hall.) 


49 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,  PLATE  LVIII 


MOLLUSCOIDEA — BRACHIOPODA 


PLATE  L1X 

PAGE 

Figs.  1,  2.     STROPHEODOXTA  VAKISTRIATA  Conrad 312 

1.  Ventral  valve.    Striae  are  nearly  equal  or  alternating  in  size. 

2.  Individual  with  alternating  striae. 

Manlius  formation,  New  York. 

Figs.  3-5.     STROPHOXELLA  GENICULATA   (Hall) 321 

Ventral,  dorsal,  and  side  views  of  a  small  individual.     Helderberg 
formation,  Keyser  member,  Cumberland.     (After  Hall.) 

Figs.  6,  7.     STROPHOXELLA  LEAVEXWORTHANA  (Hall) 322 

Dorsal  and  side  views.    New  Scotland  formation,  New  York. 

Figs.  8-10.     STROPHOXELLA  PUNCTULIFERA   (Hall) 323 

8.  Dorsal  valve. 

9.  Side  view  of  the  dorsal  valve. 

10.  Interior  of  a  more  gibbous  dorsal  valve. 
New  Scotland  formation,  New  York. 

Fig.  11.     STROPHOXELLA  KEYSERENSIS  Swartz  n.  sp 324 

Interior   of   dorsal   valve.     Helderberg   formation,   Keyser   member, 
Tonoloway. 

Fig.  12.     STROPHONELLA  HEADLEYANA  (Hall) 325 

Exterior  of  a  ventral  valve,  showing  the  peculiar  interrupted  striation. 
New  Scotland  formation,  New  York. 

Figs.  13,  14.     STROPHOXELLA  UNDAPLICATA  Swartz  n.  sp 326 

13.  Dorsal  valve. 

14.  Small  ventral  valve. 

Helderberg  formation,  New  Scotland  member,  Dawson,  W.  Va. 


50 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,  PLATE  LIX 


13 


MOLLUSCOIDEA — BRACHIOPODA 


PLATE  LX 

PAGE 

Figs.  1-3.     SCHUCHERTELLA  FROLiFicA  Schuchert  n.  sp . .  4 327 

1.  Ventral  valve. 

2.  Interior  of  dorsal  valve. 

3.  Two  small  overlapping  ventral  interiors. 

Helderberg  formation,  Keyser  member,  Keyser,  W.  Va. 

Figs.  4-9.     SCHUCHERTELLA  WOOLWORTHANA   (Hall) 328 

4.  Dorsal  view. 

5.  Ventral  valve. 

6.  Interior  of  a  large  ventral  valve. 

New  Scotland  formation,  New  York. 

7.  Dorsal    valve.      Helderberg    formation.      New    Scotland    member, 

Cedar  Cliff,  W.  Va. 

8.  9.  Internal  cast  of  ventral  and  dorsal  valves.    New  Scotland  forma- 

tion, New  York. 

Figs.  10-12.     SCHUCHERTELLA  BECRAFTEXSIS   (Clarke) 329 

10, 11.  Two  dorsal  valves. 
12.  Interior  of  ventral  valve. 

Oriskany  formation,  New  York. 

Figs.  13-16.     SCHUCHERTELLA  DECKERENSIS   (Weller) 329 

13, 14.  Ventral  valves. 

15.  Cardinal  view. 

16.  Dorsal  valve. 

Helderberg  formation,  Keyser  member,  Keyser,  W.  Va. 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,   PLATE  LX 


MOLLUSCOIDEA — BRACHIOPODA 


PLATE  LXI 

PAGE 
FigS.    1,    2.       SCHUCHERTELLA    DEFORMIS     (Hall) 331 

1.  View  of  the  dorsal  valve  and  area  of  the  ventral  valve. 

2.  Ventral  valve  of  the  same  specimen,  showing  the  contracted  and 

distorted  beak. 

Helderberg  formation,  Keyser  member,  Cumberland.     (After 
Hall.) 

Figs.  3,  4.     SCHUCHERTELLA  sixuATA  (Hall  and  Clarke) 331 

Dorsal  and  cardinal  views.  Helderberg  formation,  Keyser  member, 
Cumberland.  (After  Hall  and  Clarke.) 

Figs.  5-9.     SCHVCHERTEIXA  MARYLAxniCA  Maynard  n.  sp 332 

5,  6,  7.  Ventral,  dorsal,  and  cardinal  views  of  type  specimen. 
8,  9.  Partially  exfoliated  dorsal  valves,  Keyser,  W.  Va. 

Helderberg  formation,  Keyser  member,  Cumberland. 

Figs.  10-13.     HIPPARIOXYX  PROXIMITS  Vanuxem 333 

10, 11.  Dorsal  and  ventral  valves. 

12, 13.  Interior  ventral  and  dorsal  valves. 

Oriskany  formation,  Ridgely  member,  Cumberland.     (After 
Hall.) 

Fig.  14.     CHOXETES  ROWEI  Schuchert  n.  sp 336 

Ventral  valve.  Oriskany  formation,  Ridgely  member,  Miller's  Spring, 
near  Cumberland. 

Fig.  15.     CHOXETES  HTJDSOXICUS  Clarke 337 

Ventral  valve.  The  umbo  is  cracked.  Oriskany  formation,  Ridgely 
member,  Winchester  road. 

Fig.  16.     CHOXETES  SUBACUTIRADIATUS  Schuchert  n.  sp 335 

Ventral  valve.  Helderberg  formation,  New  Scotland  member,  Miller's 
Spring,  near  Cumberland. 

Figs.  17-19.     CHOXETES  JERSEYEXSIS  Weller 338 

17.  Ventral  valve  of  a  young  individual,  Tonoloway. 
18, 19.  Ventral  and  dorsal  valves,  Flintstone. 

Helderberg  formation,  Keyser  member. 

Fig.  20.     CHOXETES  JERSEYEXSIS  VAR.  SPIXOSUS  Maynard  n.  var 339 

Ventral  valve.    Helderberg  formation,  Keyser  member,  Hancock. 

Fig.  21.     AXOPLIA  HELDERBERGI^  Schuchert  n.  sp 340 

Ventral  valve.  X  3.  The  median  furrow  is  due  to  a  fracture.  The 
shell  is  uniformly  convex.  Helderberg  formation,  New  Scotland 
member,  21st  Bridge. 

Figs.  22-24.     AXOPLIA  XUCLEATA    (Hall) 340 

22.  Exterior  of  dorsal  valve.    X  3. 

23.  Interior  of  dorsal  valve.    X  2. 

24.  Cardinal  view  of  the  internal  cast  of  the  ventral  valve. 

Oriskany  formation,  New  York. 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,   PLATE  LX I 


MOLLUSCOIDEA — BRACHIOPODA 


PAGE 

Figs.  1,  2.     CHONOSTROPHIA  COMPLANATA    (Hall) 341 

1.  Exterior  of  ventral  valve. 

2.  Internal  cast  of  ventral  valve. 

Oriskany  formation,  New  York. 

Fig.  3.     CHONOSTROPHIA  HELDERBERGI/E  Hall  and  Clarke 342 

Ventral  valve.    Helderberg  formation,  New  Scotland  member,  Dawson. 

Figs.  4-7.     GYPIDULA  (SIEBERELLA)  COEYMANENSIS  Schuchert  n.  name 342 

4.  Interior  of  ventral  valve. 

5-7.  Dorsal,  anterior,  and  side  views. 

8.  Dorsal  view  of  large  individual. 

Coeymans  formation,  New  York. 

Figs.  9-11.     GYPIDULA     (SIEBEREJXA)      COEYMANENSIS     VAR.     PROGNOSTICS 

Schuchert  n.  var 344 

9, 10.  Ventral  and  side  views  of  unusually  large  individual. 
11.  Ventral  view  of  individual  of  usual  size. 

Helderberg  formation,  Keyser  member,  Keyser,  W.  Va. 

Figs.  12-18.     GYPIDULA    (SIEBERELLA)    COEYMANENSIS    VAR.    CORRIGANENSIS 

Maynard  n.  var 345 

12-15.  Anterior,  side,  dorsal,  and  ventral  views  of  a  large  individual. 

Cumberland. 

16-18.  Dorsal,  ventral,  and  side  views  of  type.    Devil's  Backbone. 
19.  Dorsal  view.    Keyser,  W.  Va. 

Helderberg  formation,  Keyser  member. 

Figs.  20-22.     GYPIDULA  SUBGLOBOSA  Maynard  n.  sp 346 

Ventral,    side,    and    dorsal    views.      Helderberg    formation,    Keyser 
member,  Pinto. 

Figs.  23,  24.     RHYNCHOTRETA  CUMBERLANDIA  Rowe  n.  sp 347 

Dorsal   and   side  view   of  a   large   specimen.     Oriskany   formation, 
Ridgely  member,  Cumberland. 

Figs.  25-29.     STENOCHISMA  FORMOSA  Hall 349 

25,  26.  Dorsal  and  ventral  views  of  a  large  individual. 

Becraft  formation,  New  York. 
27-28.  Side  and  ventral  view  of  smaller  individual. 
29.  Dorsal  view  of  young  specimen. 

New  Scotland  formation,  New  York. 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,   PLATE  LXII 


19 


20 


21 


22 


^^m^  26  27  28 

MOLLUSCOIDEA — BRACHIOPODA 


13 


29 


PLATE  LXIII 

PAGE 

Figs.  1-4.     STEXOCHISMA  DECKEREXSIS   (Weller) 349 

1-3.  Ventral,  side,  and  dorsal  views. 

4.  Dorsal  view  of  a  smaller  specimen. 

Helderberg  formation,  Keyser  member,  Keyser,  W.  Va. 

Figs.  5,  6.     CAMAKOTCECHIA  ?  ALTIPLICATA   (Hall) 351 

5.  View  of  ventral  valve. 

6.  Side  view  of  same. 

New  Scotland  formation,  New  York. 

Figs.  7,  8.     CAMAROTCECHIA  ORISKANIA  Rowe  n.  sp 351 

Dorsal  and  side  views  of  shell.    Oriskany  formation,  Ridgely  member, 
Cumberland. 

Figs.  9,  10.     CAMAROTCECHIA  ?  LAMELLATA  (Hall) 352 

Dorsal  and  ventral  views  of  shells.    Cobleskill  formation,  New  York. 

Figs.  11-14.     CAMAROTCECHIA   LITCHFIELDEXSIS    Schuchert 353 

Anterior,   side,   ventral,   and   dorsal   views.     Helderberg   formation, 
Keyser  member,  Cookerly. 

Figs.  15,  16.     CAMAROTCECHIA  GIGANTEA  Maynard  n.  sp 354 

Dorsal  and  ventral  views.     Helderberg  formation,  Keyser  member, 
Devil's  Backbone. 

Figs.  17-19.     CAMAROTCECHIA  (PLETHORHYNCHA)  CAMPBELLANA  (Hall)  ....   354 
Ventral,  anterior,  and  side  views.    New  Scotland  formation,  New  York. 

Figs.  20,  21.     CAMAROTCECHIA    (PLETHORHYNCHA)    PR.ESPECIOSA   Schuchert 

n.  sp 355 

20.  View  of  a  dorsal  valve. 

21.  Side  view  of  shell. 

Helderberg  formation,  Becraft  member,  near  Covington,  Va. 

Figs.  22-27.     CAMAROTCECHIA  (PLETHORHYNCHA)  SPECIOSA  (Hall) 356 

22.  23.  Dorsal  and  side  views  of  a  medium  sized  specimen. 
24,  25.  Dorsal  and  side  views  of  a  large  example. 

26,  27.  Interior  of  ventral  and  dorsal  valves. 

Oriskany  formation,  Ridgely  member,  Cumberland.     (After 
Hall.) 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,   PLATE  LXIII 


25 


MOLLUSCOIDEA — BRACHIOPODA 


PLATE  LXIV 

PAGE 

Fig.  1.     CAMABOTCECHIA  (PLETHORHYXCHA)  SPECIOSA  VAR.  RAMSAYI  (Hall).  358 
Dorsal  view  of  the  type  specimen.    Oriskany  formation,  Ridgely  mem- 
ber, Cumberland.     (After  Hall.) 

Figs.  2,  3.     CAMAROTCECHIA  (  PLETHORHYXCHA  )  BARRANDII  (Hall) 359 

2.  Internal  cast  of  ventral  valve. 

3.  Anterior  view  of  a  very  gibbous  specimen. 

Oriskany  formation,  New  York. 

Figs.  4,  5.     CAMAROTCECHIA    (PLETHORHYNCHA)    BARRAXDII   VAR.   FITCHANA 

(Hall)     359 

Dorsal  and  side  views  of  internal  cast.     Oriskany  formation,  New 
York. 

Fig.  6.     CAMAROTCECHIA  (PLETHORHYXCHA)  PLEIOPLEURA  (Conrad) 360 

Dorsal  valve.    The  drawing  is  much  restored  on  the  left.     Oriskany 
formation,  Ridgely  member,  Cumberland. 

Figs.  7-10.     UXCIXULUS  VELLICATUS    (Hall) 362 

7-9.  Dorsal,  cardinal,  and  anterior  views. 

10.  Plications  of  fold  and  sinus  enlarged  to  show  their  linear  median 
furrows  and  zigzag  lines  of  growth. 
New  Scotland  formation,  New  York. 

Figs.  11,  12.     UNCINULUS  ABRUPTUS   (Hall) 363 

Dorsal  and  ventral  views.    New  Scotland  formation,  New  York. 

Figs.  13-15.     UNCIXULUS  GLOBULUS  Schuchert 364 

13, 14.  Dorsal  and  side  views. 

15.  Anterior  view  of  a  larger  specimen. 

New  Scotland  formation,  New  York. 

Figs.  16,  17.     UXCIXULUS  NUCLEOLATUS  (Hall) 365 

Ventral    and   side   views.     Helderberg   formation,    Keyser   member, 
Keyser,  W.  Va. 

Figs.  18-20.     UXCIXULUS  NUCLEOLATUS  VAR.  AXGULATUS  Maynard  n.  var. ...   366 
Side,  ventral,  and  dorsal  views  of  type  specimen.    Helderberg  forma- 
tion, Keyser  member,  Cumberland. 


55 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,   PLATE  LXIV 


MOLLUSCOIDEA ERACHIOPODA 


|| 


PLATE  LXV 

PAGE 

Figs.  1-6.     UXCIXULUS  GORDOXI  Maynard  n.  sp  ...........................   367 

1,  2.  Dorsal  and  ventral  views. 

3,  4.  Anterior  and  ventral  views  of  a  smaller  specimen. 

5,  6.  Anterior  and  side  views  of  a  gibbous  form.     . 

Helderberg  formation,  Keyser  member,  Cash  Valley. 

Figs.  7,  8.     UXCIXULUS  KEYSEREXSIS  Schuchert  n.  sp  ....................   368 

Dorsal    and    side   views.      Helderberg    formation,    Keyser    member, 
Keyser,  W.  Va. 

Figs.  9-14.     UXCIXULUS  CONVEXORUS  Maynard  n.  sp  ......................   368 

9.  Dorsal  view  of  individual  with  coarse  plications. 
10-13.  Side,  dorsal,  ventral,  and  anterior  views. 
14.  View  of  large  ventral  valve  with  fine  plications. 

Helderberg  formation,  Keyser  member,  Keyser,  W.  Va. 

Figs.  15-17.     WILSOXIA  GLOBOSA  Weller  .................................   369 

Side,    dorsal,    and    ventral    views.      Helderberg    formation,    Keyser 
member,  Cash  Valley. 

Figs.  18-20.     WILSOXIA  CF.  GLOBOSA  Weller  ..............................   370 

Side,  ventral,  and  dorsal  views.    Helderberg  formation,  Keyser  mem- 
ber, Tonoloway. 

Figs.  21,  22.     EATOXIA   SIXGULARIS    (Vanuxem)  .........................   371 

Dorsal  and  ventral  views.    Helderberg  formation,  New  Scotland  mem- 
her,  Corriganville. 

Figs.  23-28.     EATOXIA  PECULIARIS   (Conrad)  .............................   372 

23,  24.  Dorsal  and  ventral  views. 

25,  26.  Interior  of  dorsal  and  ventral  valves.     (After  Hall.) 
Oriskany  formation,  Ridgely  member,  Cumberland. 
27,  28.  Ventral  and  dorsal  views  of  internal  cast.    New  Scotland  forma- 
tion, New  York. 

Figs.  29,  30.     EATOXIA  WHITFIELDI  Hall  ................................   373 

29.  Ventral  valve.    X  2. 

30.  A  water-worn  dorsal  valve.    X  2. 

Oriskany  formation,  Ridgely  member,  Cumberland. 

Figs.  31-35.     EATOXIA  MEDIALIS    (Vanuxem)  ............................   374 

31.  Dorsal  view  of  a  large  specimen. 

32.  33.  Ventral  and  side  views. 

34,  35.  Dorsal  and  ventral  views  of  internal  cast  of  a  small  individual. 
New  Scotland  formation,  New  York. 

Figs.  36-38.     EATOXIA  SINUATA  Hall  ....................................   375 

36,  37.  Dorsal  and  ventral  views. 
38.  Interior  of  ventral  valve. 

Oriskany  formation,  Ridgely  member,  Cumberland. 


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LOWER   DEVONIAN,   PLATE  LXV 


37 


MOLLUSCOIDEA — BRACK  IOPODA 


PLATE  LXVI 

PAGE 

Fig.  1.     EATONIA  SINUATA  Hall 375 

Internal  cast  of  ventral  valve.    Oriskany  formation,  Ridgely  member, 
Cumberland.     (After  Hall.) 

Figs.  2,  3.     EATONIA  HARTLEYI  Schuchert  n.  sp 376 

Dorsal  and  side  views.    Oriskany  formation,  Ridgely  member,  Martin 
Mountain,  Allegany  County. 

Fig.  4.     RHYNCHONELLA  ( ?)  BIALVEATA  Hall 377 

Dorsal  view.    X  2.    New  Scotland  formation,  New  York. 

Figs.  5,  6.     RENSSEL^RIA  MUTABILIS    (Hall) 378 

Dorsal  and  ventral  views.     Helderberg  formation,  Keyser  member, 
Cumberland. 

Figs.  7-9.     RENSSEL^ERIA  MUTABILIS  VAR 378 

Ventral,    dorsal,    and    side    views.      Helderberg    formation,    Keyser 
member,  Tonoloway. 

Figs.  10-12.     RENSSEL^RIA  SUBGLOBOSA  Weller 379 

10.  Ventral  valve. 

11, 12.  Ventral  and  side  views  of  an  average  individual. 

Helderberg  formation,  Becraft  member,  Cherry  Run,  W.  Va. 

Fig.  13.     RENSSEL.ERIA  SUBGLOBOSA  VAR.  AVUS  Schuchert  n.  var 380 

Ventral   valve,    slightly    distorted.      Helderberg    formation,    Becraft 
member,  Cherry  Run,  W.  Va. 

Fig.  14.     RENSSEL^ERIA  SUBGLOBOSA  VAR,  CRASSA  Schuchert  n.  var 381 

Ventral   valve   showing   the   coarser   striae.     Helderberg   formation, 
Becraft  member,  Licking  Creek,  Pa. 

Figs.  15-17.     RENSSEL^RIA  CIRCULARIS  Schuchert  n.  sp 381 

Ventral,  dorsal,  and  side  views.     Oriskany  formation,  Ridgely  mem- 
ber, Cumberland. 

Figs.  18-24.     RENSSEL^ERIA  MARYLANDICA  Hall 382 

18, 19.  Dorsal  and  side  views  of  a  small  specimen. 
20,  21.  Dorsal  and  side  views  of  an  average  specimen. 

22.  Interior  of  ventral  valve. 

23.  Interior  of  dorsal  valve  to  show  the  large  crural  plates  and  the 

pointed  brachidium  which  supports  the  fleshy  arms. 

24.  Median  section  of  shell  to  show  the  various  plates,  thickening  of 

the  posterior  region  of  the  valves,  and  the  position  of  the  jugum. 
Oriskany  formation,  Ridgely  member,  Cumberland.     (After 
Hall.) 

Fig.  25.     RENSSEL.^RIA  MARYLAXDICA  VAR.  SYMMETRICA  Schuchert  n.  var.  .   384 
Dorsal  view.    Oriskany  formation,  Ridgely  member,  Cumberland. 

Figs.  26-28.     RENSSEL^RIA  KEYSERENSIS  Swartz  n.  sp 384 

Ventral,  dorsal,  and  side  views  of  type.    Helderberg  formation,  Keyser 
member,  %  mile  southwest  of  Rawlings. 

57 


MARYLAND  GEOLOGICAL  SURVEY 


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24 


MOLLUSCOIDEA — BRACHIOPODA 


PLATE  LXVII 

PAGE 

Figs.  1-3.     REXSSEL.ERIA  (BEACHIA)  PROAVITA  Schuchert  n.  sp 385 

1.  Ventral  valve.    X  1%. 

2,  3.  Dorsal  and  side  views  of  another  specimen.    X  1%. 

Helderberg  formation,  Keyser  member,  Pinto. 

Figs.  4-6.     RENSSEIJERIA  (BEACHIA)  CUMBEBLAXDM:  (Hall) 386 

Dorsal,  ventral,  and  side  views.     Oriskany  formation,  Ridgely  mem- 
ber, Cumberland. 

Figs.  7-15.     RENSSEL/ERIA  (BEACHIA)  SUESSANA  (Hall) 387 

7,  8.  Dorsal  and  side  views  of  a  small  specimen. 

9, 10.  Same  of  an  average  specimen. 

11.  Dorsal  view  of  an  elongate  specimen. 

12, 13.  Dorsal  and  side  views  of  a  large  specimen. 

14.  Interior  of  dorsal  valve. 

15.  Longitudinal  section  of  valves  showing  crura  and  appendages. 

Oriskany  formation,  Ridgely  member,  Cumberland.      (After 
Hall.) 

Fig.  16.     RENSSEL.ERIA  (BEACHIA)  SUESSAXA  VAR.  IMMATURA  Schuchert  n. 

var 388 

Dorsal  valve.     X  1%.     Oriskany  formation,   Shriver  member,  Cash 
Valley,  Cumberland. 

Figs.  17-19.     RENSSEL^RIA  (BEACHIA)  OVALIS  (Hall) 389 

17, 18.  Ventral  and  side  views. 
19.  Internal  cast  of  ventral  valve. 

Oriskany  formation,  New  York. 

Figs.  20-24.     ORISKANIA  LUCERNA  Schuchert  n.  sp 390 

20-22.  Dorsal,  ventral,  and  side  views. 

23,  24.  Interior  of  ventral  and  dorsal  valves.    X  2. 

Oriskany  formation,  Ridgely  member,  Cumberland. 

Fig.  25.     TROPIDOLEPTUS    CARINATTJS    (Conrad) 390 

Ventral  valve.    Oriskany  formation,  Ridgely  member,  Cumberland. 

Figs.  26-28.     ATRYPA  RETICULARIS   (Linne) 392 

26,  27.  Dorsal  and  side  views. 
28.  Interior  of  ventral  valve. 

New  Scotland  formation,  New  York. 


53 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,   PLATE  LXVII 


24 


MOLLUSCOIDEA — BRACHIOPODA 


PLATE  LXVIII 

PAGE 

Figs.  1-3.     ATRYPA  ?  BICOXVEXA  Maynard  n.  sp 393 

1,  2.  Ventral  and  dorsal  views.    Keyser,  W.  Va. 

3.  Dorsal  view  of  another  example.    Cash  Valley,  Cumberland. 

Helderberg  formation,  Keyser  member. 

Figs.  4-6.     ATKYPINA  IMBRICATA  (Hall) 394 

4,  5.  Ventral  and  dorsal  views. 
6.  Dorsal  view.    X  3. 

New  Scotland  formation.  New  York. 

•      '4  f 
fc^a^ovnE  ^*^ 

Figs.  7,  8.     SPIRIFER'  MAdROPLEURUs    (Conrad) 396 

Dorsal  and  ventral  valves.    Helderberg  formation,  New  Scotland  mem- 
ber, Corriganville. 

Figs.  9-16.     SPIRIFER  CUMBERLANDI.E  Hall 398 

9-11.  Dorsal,  ventral,  and  side  views  of  a  small  specimen. 
12-14.  Same  views  of  an  average  specimen. 
15, 16.  Interior  of  ventral  and  dorsal  valves. 

Oriskany  formation,  Ridgely  member,  Cumberland.     (After 
Hall.) 

Figs.  17-22.     SPIRIFER  MODESTUS  Hall 399 

17, 18.  Dorsal  and  front  view. 

19-21.  Dorsal,  ventral,  and  side  views  of  a  larger  individual. 

22.  Interior  of  ventral  valve. 

Helderberg  formation,  Keyser  member,  Cumberland.     (After 
Hall.) 

Figs.  23,  24.     SPIRIFER  MODESTU s  VAR.  PLICATUS  Maynard  n.  var 400 

Dorsal  and  ventral  views  of  type.     Helderberg   formation,   Keyser 
member,  Keyser,  W.  Va. 

Figs.  25-29.     SPIRIFER  OCTOCOSTATUS  Hall 401 

25-28.  Ventral,  dorsal,  side,  and  cardinal  views. 
29.  Interior  of  ventral  valve. 

Helderberg  formation,  Keyser  member,  Cumberland.     (After 
Hall.) 

Figs.  30,  31.     SPIRIFER  PAUCICOSTATUS  Schuchert  n.  sp 402 

Internal  casts  of  dorsal  and  ventral  valves.     X  3.     Oriskany  forma- 
tion, Shriver  member,  Cash  Valley. 

Figs.  32,  33.     SPIRIFER  VAXVXEMI  Hall 403 

Ventral  and  dorsal  views.    Manlius  formation,  New  York. 

Figs.  34,  35.     SPIRIFER  VAXUXEMI  VAR.  PROGXOSTICA  Schuchert  n.  var 403 

Ventral  and  dorsal  views.     Helderberg  formation,  Keyser  member, 
%  mile  southwest  of  Rawlings. 


MARYLAND  GEOLOGICAL  SURVEY 


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PLATE  LXIX 

PAGE 

Figs.  1-3.     SPIBIFEB  VANUXEMI  VAB.  PROGXOSTICUS  Schuchert  n.  var 403 

1.  Dorsal  view  of  a  large  specimen.    X  2. 

2,  3.  Anterior  and  side  views  of  a  smaller  individual.    X  2. 

Helderberg  formation,  Keyser  member,  Pinto. 

Figs.  4-6.     SPIRIFEK  PERLAMELLOSUS  Hall 397 

Dorsal,  ventral  and  side  views.    Helderberg  formation,  New  Scotland 
member,  Cumberland. 

Fig.  7.     SPIRIFEK  ERIENSIS  Grabau 404 

Ventral  valve.    Helderberg  formation,  Keyser  member,  Cash  Valley. 

Figs.  8-10.     SPIRIFER  CYCLOPTERUS  Hall 406 

8,  9.  Dorsal  and  side  views  of  average  specimen. 
10.  Ventral  valve  of  a  smaller  specimen. 

New  Scotland  formation,  New  York. 

Figs.  11-14.     SPIRIFER  TRIBULIS  Hall 407 

11-13.  Dorsal,  ventral,  and  side  views. 

14.  A  portion  of  the  surface  lamellae  much  magnified  to  show  the 
finely  spinose  margins. 

Helderberg  formation,  New  Scotland  member,  Cumberland. 
(After  Hall.) 

Figs.  15,  16.     SPIRIFER  ANGULARIS  Schuchert  n.  sp 409 

Dorsal  and  ventral  views  of  a  large  specimen.     Oriskany  formation, 
Ridgely  member,  Cumberland. 

Figs.  17-21.     SPIRIFER  INTERMEDIUS  Hall 409 

17, 18.  Ventral  and  dorsal  views  of  Cumberland  specimen. 

19.  Ventral  valve  with  a  wider  sinus.    Cumberland. 

20,  21.  Dorsal  and  ventral  views  of  an  average  specimen  from  Warren 

Point,  Penna. 
Oriskany  formation,  Ridgely  member. 


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21 


MOLLUSCOIDEA — ERACHIOPODA 


PLATE  LXX 

PAGE 

Figs.  1-5.     SPIRIFER  MURCHISONI  Castelnau 411 

1.  Dorsal  view  of  an  average  specimen.    Cumberland. 

2.  Internal  cast   of  ventral  valve   retaining  portion   of  shell,  same 

locality. 

3-5.  Dorsal,  ventral,  and  side  views  of  the  form  with  angular  plica- 
tions.   Warren  Point,  Penna. 
Oriskany  formation,  Ridgely  member. 

Figs.  6,  7.     SPIRIFKR  MURCHISONI  YAR.  MARYLANDICUS  Schuchert  n.  var. . . .   413 
Dorsal  and  side  views.     Oriskany  formation,  Ridgely  member,  Cum- 
berland. 

Figs.  8-10.     SPIRIFER  HARTLEYI  Schuchert  n.  sp . . . ; 413 

Dorsal,  ventral,  and  side  views  of  the  type.     Oriskany  formation, 
Ridgely  member,  Cumberland. 

Figs.  11-13.     SPIRIFER  PERDEWI  Schuchert 414 

11, 12.  Dorsal  and  ventral  views  of  a  small  specimen. 

13.  Dorsal  view  of  a  large  specimen. 

Oriskany  formation,  Ridgely  member,  Cumberland. 

Figs.  14-16.     SPIRIFER  TRIBUARIUS  Schuchert  n.  sp 414 

14.  Dorsal  view. 

15, 16.  Dorsal  and  ventral  views  of  another  individual. 

Oriskany  formation.  Shriver  member,  Cumberland. 


61 


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PLATE  LXXI  w 

PAGK 

Figs.  1-9.     SPIRIFER  AREXOSUS   (Conrad) 415 

1,  2.  Dorsal  and  ventral  views  of  a  young  individual. 

3-6.  Dorsal,  side,  cardinal  and  anterior  views  of  an  average  specimen. 

7.  The  spiralia  silicified. 

8,  9.  Exterior  and  interior  of  a  large  ventral  valve. 

Oriskany   formation,   Ridgely  member,  Cumberland.    (After 
Hall.) 

Figs.  10-16.     CYRTINA  ROSTRATA   (Hall) 423 

10, 11.  Cardinal  and  side  views  of  a  large  specimen. 

12.  Interior  of  ventral  valve. 

13.  Dorsal  valve. 

14.  Anterior  view  of  an  alate  specimen. 

15, 16.  Dorsal  and  cardinal  views  of  a  small  specimen. 
Oriskany  formation,  New  York. 

Fig.  17.     SPIRIFER  PROAVITUS  Schuchert  n.  sp 418 

Dorsal  view  of  type.    Helderberg  formation,  New  York. 


MARYLAND  GEOLOGICAL  SURVEY 


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MOLLUSCOIDEA — BRACHIOPODA 


PLATE  LXXII 

PAGE 

Fig.  1.     SPIRIFER  ARENOSUS    (Conrad) 415 

Internal  cast  of  ventral  valve.    Oriskany  formation,  New  York. 

Figs.  2,  3.     SPIRIFER  CONCINNUS  Hall 417 

Dorsal  and  ventral  views.    Becraft  formation,  New  York. 

Fig.  4.     SPIRIFER  COXCINNOIDEUS  Schuchert  n.  sp 419 

Internal  cast  of  dorsal  valve.  Oriskany  formation,  Ridgely  member, 
Pendleton  County,  W.  Va. 

Figs.  5-7.     SPIRIFER  GORDONI  Schuchert  n.  sp 420 

Dorsal,  ventral,  and  side  views  of  the  type.  Oriskany  formation, 
Ridgely  member,  Cumberland. 

Figs.  8-10.     RETICULARIA  BICOSTATA  (Vanuxem) 420 

8,  9.  Ventral  and  dorsal  views. 

10.  Dorsal  view  of  a  specimen  showing  stronger  plications. 
Niagara  formation,  New  York. 

Figs.  11,  12.     METAPLASIA  PYXIDATA  (Hall) 422 

Dorsal  and  ventral  views.  X  2.  Oriskany  formation,  Ridgely  mem- 
ber, Cumberland. 

Figs.  13-15.     RHYNCHOSPIRA  RECTIROSTRIS  (Hall) 424 

Dorsal,  ventral,  and  side  views  of  the  type.  Oriskany  formation, 
Ridgely  member,  Cumberland.  (After  Hall.) 

Figs.  16-25.     RHYXCHOSPIRA  GLOBOSA   (Hall) 425 

16-18.  Ventral,    dorsal,    and    side  views   of   an    exfoliated    specimen. 

Tonoloway. 

19.  Side  view  of  unusually  large  and  gibbous  specimen.    Tonoloway. 
20-22.  Dorsal,  ventral,  and  side  views.    Cumberland. 

Helderberg  formation,  Keyser  member. 
23.  Side  view  of  gibbous  specimen. 
24-25.  Dorsal  and  ventral  views. 

New  Scotland  formation,  New  York. 

Figs.  26-30.     RHYNCHOSPIRA  FORMOSA  Hall 426 

26.  Side  view  of  doubtfully  determined  specimen  having  striae  coarser 
than  usual,  beak  erect.  Helderberg  formation,  Keyser  member. 
Cash  Valley. 

27-29.  Dorsal,  ventral  and  side  views. 
30.  Dorsal  view  of  individual  with  finer  plications. 
New  Scotland  formation,  New  York. 


68 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER  DEVONIAN,   PLATE  LXXII 


•j. 

8 


t 
P 


13 


m 

14  15 


20 


19 


21 


22 


v, 
23 


26 


, 


27 


28 


11 


12 


16 


17 


18 


24 


25 


29 


30 


MOLLUSCOIDEA — BRACHIOPODA 


PLATE  LXXIII 

PAGE 

Figs.  1,  2.     TREMATOSPIRA  SIMPLEX  Hall  ? 427 

Dorsal  and  ventral  views.  X  2.  Helderberg  formation,  New  Scotland 
member,  Devil's  Backbone. 

Figs.  3,  4.     TREMATOSPIRA  MULTISTRIATA   (Hall) 428 

Dorsal  and  ventral  views.  Helderberg  formation,  New  Scotland  mem- 
ber, Corriganville. 

Figs.  5-7.     TREMATOSPIRA  DEWEYI    (Hall) 429 

Dorsal,  ventral  and  side  views.    New  Scotland  formation,  New  York. 

Figs.  8,  9.     TREMATOSPIRA  EQUISTRIATA  Hall  and  Clarke 430 

Dorsal  and  ventral  views.  Helderberg  formation,  New  Scotland  mem- 
ber, Corriganville. 

Figs.  10-12.     NUCLEOSPIRA  VENTRICOSA    (Hall) 430 

Dorsal,  ventral,  and  side  views.    New  Scotland  formation,  New  York. 

Figs.  13,  14.     NUCLEOSPIRA  ELEGANS  Hall 431 

Dorsal  and  ventral  views.  The  sinus  in  the  dorsal  valve  is  drawn  too 
angularly.  X  1%.  Helderberg  formation,  New  Scotland  mem- 
ber, Corriganville. 

Figs.  15-17.     NUCLEOSPIRA  SWARTZI  Maynard  n.  sp 432 

Ventral,  dorsal  and  side  views.  Helderberg  formation,  Keyser  mem- 
ber, Keyser,  W.  Va. 

Figs.  18,  19.     ANOPLOTHECA  CONCAVA   (Hall) 434 

—*/*£•  Dorsal  and  ventral  views.     X  3.    Helderberg  formation,  New  Scotland 

I  member,  Corriganville. 

Figs.  20,  21.     ANOPLOTHECA  CONCAVA  VAR.  TONOLOWAYENSIS  Swartz  n.  var..   434 
Dorsal  and  ventral  views.     X  2.    Helderberg  formation,  Keyser  mem- 
ber, Tonoloway. 

Figs.  22,  23.     ANOPLOTHECA  EQUISTRIATA  Schuchert  n.  sp 435 

Dorsal  and  ventral  views.  X  2.  Oriskany  formation,  Ridgely  mem- 
ber, Cumberland. 

Figs.  24-26.     ANOPLOTHECA  DICHTOMA  (Hall) 435 

24,  25.  Dorsal  and  ventral  views. 

26.  Anterior  view  to  show  concave  dorsal  valve. 

Oriskany  formation,  Ridgely  member,  Cumberland.     (After 
Hall.) 

Figs.  27,  28.     ANOPLOTHECA  (LEPTOCCELIA)  FIMBRIATA  (Hall) 436 

Dorsal  and  ventral  views.  Oriskany  formation,  Ridgely  member,  Cum- 
berland. (After  Hall.) 

Figs.  29-33.     ANOPLOTHECA  (LEPTOCCELIA)  FLABELLITES  (Conrad) 438 

29-31.     Dorsal,  ventral,  and  side  views. 
32,  33.  Interior  ventral  and  dorsal  valves. 

Oriskany  formation,  Ridgely  member,  Cumberland.     (After 
Hall.) 

Figs.  34-36.     WHITFIELDELLA  ( ?)  PROSSERI  Grabau 439 

Ventral,  dorsal,  and  side  views.  Helderberg  formation,  Cherry  Run, 
W.  Va. 

Figs.  37-40.     WHITFIELDELLA  ( ?)   NUCLEOLATA  Hall 441 

37.  Dorsal  view  of  small  specimen. 
38-40.  Ventral,  dorsal,  and  side  views. 

Cobleskill  formation,  New  York. 

Figs.  41,  42.     WHITFIELDELLA  (?)  MINUTA  Maynard  n.  sp 442 

Dorsal  and  ventral  views.  X  5.  Helderberg  formation,  Keyser  mem- 
ber, Round  Top. 

Figs.  43-46.     MERISTELLA  PR.ENUNTIA  Schuchert  n.  sp 443 

43.  Dorsal  view  of  specimen  with  strong  median  fold. 
44-46.  Ventral  valves  showing  differences  in  development  of  sinuses. 
Helderberg  formation,  Keyser  member,  Keyser,  W.  Va. 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,   PLATE  LXXIII 


MOLLUSCOIDEA — BRACHIOPODA 


PLATE  LXXIV 

PAGE 

Figs.  1-4.     MERISTELLA  PR^ENUNTIA  Schuchert  n.  sp 443 

I.  Dorsal  view. 

2-4.  Dorsal,  side,  and  ventral  views  of  a  large  and  gibbous  specimen. 
Helderberg  formation,  Keyser  member,  Keyser,  W.  Va. 

Figs.  5-8.     MERISTELLA   ARCUATA    (Hall ) 444 

5,  6.  Dorsal  and  side  views. 

7.  Anterior  view  to  show  depth  of  ventral  sinus. 

8.  Small  ventral  valve. 

New  Scotland  formation,  New  York. 

Figs.  9-11.     MERISTELLA  LATA    (Hall) 445 

9, 10.  Ventral  view  of  different  specimens. 

II.  Dorsal  view  of  another  specimen. 

Oriskany  formation,  Ridgely  member,  Warren  Point,  Penna. 

Figs.  12,  13.     MERISTELLA  LENTIFORMIS  Clarke 446 

Dorsal  and  side  views  of  type.    Oriskany  formation,  New  York. 

Figs.  14,  15.     MERISTELLA  ROSTELLATA  Schuchert  n.  sp 447 

Dorsal  and  ventral  views  of  type.    Oriskany  formation,  Ridgely  mem- 
ber.   Cumberland. 

Figs.  16-19.     MERISTELLA  SYMMETRICA  Schuchert  n.  sp 448 

16, 17.  Dorsal  and  side  views  of  a  small  individual. 

18.  Ventral  view  of  a  large  specimen. 

19.  Ventral  view  of  an  unusually  large  specimen. 

Oriskany  formation,  Ridgely  member,  Cumberland. 

Figs.  20-24.     MERISTA  TYPA   (Hall) 449 

20.  Dorsal  view. 

21.  22.  Interiors  of  ventral  valves. 

23.  A  longitudinal  section  of  fig.  22. 

24.  Internal  cast  of  ventral  valve. 

Helderberg  formation,  Keyser  member,  Cumberland.*   (After 
Hall.) 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,   PLATE  LXXIV 


MOLLUSCOIDEA — BRACHIOPODA 


PLATE  LXXV 

PAGE 

Fig.  1.     GRAMMYSIA   sp 450 

Anterior  part  of  left  valve.     Helderberg  formation,  Keyser  member, 
Keyser,  W.  Va. 

Fig.  2.     LEPTODESMA   (?)    sp 451 

Internal  cast  of  right  valve.     Oriskany  formation,  Ridgely  member, 
Rock  Enon  Spring,  W.  Va. 

Figs.  3,  4.     MYTILARCA  MARYLANDICA  Ohern  n.  sp 452 

3.  Internal  cast  of  left  valve. 

4.  Anterior  view  of  internal  cast. 

Helderberg  formation,  Cumberland. 

Figs.  5,  6.     MYTILARCA  CORUIFORMIS    (Hall) 452 

5.  Profile  view  from  the  anterior  side  of  the  shell. 

6.  View  of  the  right  valve,  having  the  posterior  cardinal  extension 

abraded. 
New  Scotland  formation,  New  York. 

Fig.  7.     MYTILARCA  ( PLETHOMYTILUS )  ROWEI  Ohern  n.  sp 453 

Left  valve.    Oriskany  formation,  Ridgely  member,  Hancock. 

Figs.  8-10.     AMPHICCELIA  TJLRICHI  Maynard  n.  sp 453 

8.  Anterior  view  of  internal  cast. 

9.  Internal  cast  of  right  valve. 
10.  Left  valve. 

Helderberg  formation,  Keyser  member,  Keyser,  W.  Va 


66 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,   PLATE  LXXV 


MOLLUSCA — PELECYPODA 


PLATE  LXXVI 

PAGE 

Fig.  1.     PALEOPINNA  LATA  Ohern  n.  sp 454 

Left  valve.    Oriskany  formation,  Ridgely  member,  Hancock. 

Figs.  2-4.     ACTINOPTERIA  COMMUNIS    (Hall) 455 

2.  Left  valve  of  a  large  specimen.    Helderberg  formation,  New  Scot- 
land member,  Cumberland. 

3, 4.  Left  and  right  valves.     Oriskany  formation,  Ridgely  member, 
Cumberland. 

Fig.  5.     ACTINOPTERIA  TEXTILIS    (Hall) 456 

Left  valve.     Helderberg  formation,  New  Scotland  member,  Cumber- 
land. 

Fig.  6.     ACTIXOPTERIA  RETICULATA  Weller 459 

Left  valve.    Helderberg  formation,  Keyser  member,  Keyser,  W.  Va. 

Fig.  7.     AVICULA  RECTICOSTA  Hall 460 

Right  valve.    Oriskany  formation,  New  York. 


07 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER  DEVONIAN,  PLATE  LXXVI 


MOLLUSCA PELECYPODA 


PLATE  LXXVII 

PAGE 
FigS.    1,    2.      ACTINOPTEKIA  TEXTILIS  VAR.  ARENARIA  Hall 457 

1.  External  cast  of  left  valve.    X  %. 

2.  Left  valve  weathered  and  exfoliated.    X  %. 

Oriskany  formation,  New  York. 


68 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER  DEVONIAN,  PLATE  LXXVII 


MOLLUSCA —  PELECYPODA 


PLATE  LXXVIII 

PAGE 

Figs.  1,  2.     ACTIXOPTERIA  VIRGINICA  Ohern  n.  sp 458 

1.  Imperfect  left  valve,  questionably  referred  to  this  species.  Hancock. 

2.  Left  valve  of  type.    Four  miles  southwest  of  Keyser,  W.  Va. 

Oriskany  formation,  Ridgely  member. 

Fig.  3.     AVICULOPECTEX  ?  CUMBERLAXDEXSIS  Ohern  n.  sp 460 

Left  valve  of  type.    Helderberg  formation. 

Fig.  4.     AVICULOPECTEN  TEXT-ILAMELLATI'S  Hall 461 

Right  valve  partly  exfoliated.    New  Scotland  formation,  New  York. 

Fig.  5.     MEGAMBOXIA  LAMELLOSA  Hall 462 

Left  valve.    Oriskany  formation,  Ridgely  member,  Cumberland. 

Figs.  6,  7.     CYPRICARDIXIA  CF.  LAMELLOSA  Hall 463 

6.  Left  valve. 

7.  The  same  enlarged  to  nearly  three  diameters. 

New  Scotland  formation,  New  York. 

Fig.  8.     CYPRICARDIXIA  SUBLAMELLOSA  Hall 463 

Right  valve.    New  Scotland  formation,  New  York. 

Figs.  9,  10.     ILIOXIA  SIXUATA  Hall 464 

9.  The  right  valve  of  the  specimen. 
10.  Cardinal  view  of  the  same. 

Manlius  formation,  New  York. 

Figs.  11,  12.     PTERIXEA  HALLI   Clarke 450 

11.  Left  valve. 

12.  Left  valve  partially  exfoliated. 

New  Scotland  formation,  New  York. 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,   PLATE  LXXVIII 


11 


MOLLUSCA — PELECYPODA 


PLATE  LXXIX 

PAGE 

Figs.  1,  2.     BELLEROPHOX  CF.  AURICULATUS  Hall 465 

Dorsal  and  ventral  views.    Helderberg  formation,  Cumberland. 

Figs.  3,  4.     BELLEROPHON  HELDERBERGI.E  Swartz  n.  sp 466 

Side  and  dorsal  views  of  the  type.     Helderberg  formation,  Keyser 
member,  Cash  Valley. 

Figs.  5,  6.     CYRTOLITES  EXPANSUS  Hall 466 

Anterior  and  side  views.    Oriskany  formation,  New  York. 

Fig.  7.     LOXONEMA  FITCHI  Hall 467 

Cast  somewhat  flattened.    New  Scotland  formation,  New  York. 

Fig.  8.     LOXONEMA  sp 468 

Internal  cast.    Helderberg  formation,  Keyser  member,  Cash  Valley. 

Fig.  9.     HoLOPEA  sp 468 

Ventral  view.    Helderberg  formation,  Cumberland. 

Figs.  10-12.     ORTHONYCHIA  TORTUOSA  (Hall) 469 

Views  of  shell  in  different  positions.     Oriskany  formation,  Ridgely 
member,  Cumberland. 

Figs.  13,  14.     PLATYCERAS  NODOSUM  Conrad 469 

13.  Large,  partially  exfoliated  specimen. 

14.  Internal  cast  of  smaller  specimen. 

Oriskany    formation,   Ridgely   member,    east   side   Nicholas 
Mountain. 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,   PLATE  LXXIX 


MOLLUSC  A — GASTROPODA 


PLATE  LXXX 

PAGE 

Fig.  1.     PLEUROTOMARIA  LABROSA  Hall 465 

Dorsal  view  of  partially  exfoliated  specimen,  preserving  spiral  band. 
Also  an  enlargement  of  the  surface  markings.  Becraft  forma- 
tion, New  York. 

Figs.  2-9.     PLATYCERAS  GEBHARDI  Conrad 470 

2.  Lower  and  upper  views  of  a  large  specimen. 

3,  4.  Upper  and  ventral  views  of  small  specimen. 

5.  Upper  view  of  very  large  specimen  from  Warren  Point,  Penna. 

6,  7.  Ventral  and  upper  views  of  specimen  with  free  and  expanded 

peristome. 

8,  9.  Upper  and  lower  views  of  specimen  with  free  but  not  expanded 
peristome. 

Oriskany  formation,  Ridgely  member,  Cumberland.     (All  but 
fig.  5  after  Hall.) 


71 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,   PLATE  LXXX 


MOLLUSCA — GASTROPODA 


PLATE  LXXXI 

PAGE 

Figs.  1-9.     PLATYCERAS  GEBHAKDI  VAR.  VEXTRICOSUM  Conrad 471 

1,  2.  Upper  and  ventral  views. 

3,  4.  Ventral  and  upper  views  of  a  small  individual. 

5,  6.  Upper  and  ventral  views  of  a  specimen  of  medium  size. 

7,  8.  Upper  and  ventral  views  of  a  large  specimen  with  contiguous 

volutions. 
9.  Upper  view  showing  a  broad  sinuosity  in  the  margin. 

Oriskany  formation,  Ridgely  member,  Cumberland.     (After 
Hall.) 


73 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,   PLATE  LXXXI 


MOLLUSCA — GASTROPODA 


PLATE  LXXXII 

PAGE 

Figs.  1-6.     PLATYCERAS  MAGNIFICUM  Hall 472 

1.  Ventral  view  of  a  young  shell. 

2,  3.  Dorsal  and  ventral  views  of  a  larger  specimen  with  free  volutions. 

4.  Ventral  view  of  a  specimen  with  the  volutions  free  and  the  peris- 

tome  less  expanded. 

5.  Upper  view. 

6.  Upper  view  of  the  spire  of  a  large  specimen  in  which  all  the  parts 

are  symmetrical  and  well  preserved,  and  the  volutions  are  free 
except  at  the  extreme  apex. 

Oriskany  formation,  Ridgely  member,  Cumberland.     (After 
Hall.) 

Figs.  7,  8.     PLATYCERAS  STJBFALCATUM  Ohern  n.  sp 472 

Side  and  dorsal  views.     Oriskany  formation,  Ridgely  member,  Han- 
cock. 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,   PLATE  LXXXII 


MOLLUSCA GASTROPODA 


PLATE  LXXXIII 

PAGE 

Figs.  1-3.     PLATYCERAS  SUBFALCUM  Ohern  n.  sp 472 

1.  Upper  view  of  a  large  specimen. 

2,  3.  Views  of  type. 

Oriskany  formation,  Ridgely  member,  Hancock. 

Fig.  4.     PLATYCERAS  PATULUM  Hall 473 

Ventral  view.     Oriskany  formation,  Ridgely  member,  Cumberland. 
(After  Hall.) 

Figs.  5,  6.     PLATYCERAS  REFLEXUM   Hall 473 

5.  Ventral  view  of  a  small  specimen. 

6.  Upper  view  of  a  larger  specimen. 

Oriskany  formation,  Ridgely  member,    Cumberland.     (After 
Hall.) 


74 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,   PLATE  LXXXIH 


MOLLUSCA — GASTROPODA 


PLATE  LXXXIV 

PAGE 

Figs.  1,  2.     PLATYCEBAS  REFLEXUM  Hall 473 

Two  views  of  a  specimen  in  which  the  aperture  is  obtusely  quad- 
rangular. Oriskany  formation,  Ridgely  member,  Cumberland. 
(After  Hall.) 

Figs.  3,  4.     PLATYCERAS  ?  CALLOSUM  Hall 474 

Dorsal  and  ventral  views.  Oriskany  formation,  Ridgely  member, 
Cumberland.  (After  Hall.) 

Figs.  5,  6.     PLATYCERAS  SIXUATUM  Hall  ? 474 

5.  Upper  view   of   a    small   specimen,   showing   the   deep   marginal 

sinuosity  and  the  strong  wrinkled  surface. 

6.  Upper  view  of  a  larger  specimen. 

New  Scotland  formation,  New  York. 

Figs.  7,  8.     PLATYCERAS  TRILOBATUM  Hall 475 

Ventral  and  upper  views.  [The  striae  represented  between  the  aper- 
ture and  the  next  volution  do  not  exist  in  the  specimen.]  New 
Scotland  formation,  New  York. 


75 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,   PLATE  LXXXIV 


3  4 

MOLLUSCA — GASTROPODA 


PLATE  LXXXV 

PAGE 

Figs.  1,  2.     PLATYCERAS  TENUILIRATUM  Hall 476 

Upper  and  dorsal  views  of  a  large  individual.    New  Scotland  forma- 
tion, New  York. 

Fig.  3.     PLATYCERAS  ANGULARE  Rowe  n.  sp 476 

Dorsal  view  of  type.     Oriskany  formation,  Ridgely  member,  Warren 
Point,  Penna. 

Figs.  4-6.     PLATYCERAS   MULTISINUATUM    Hall 477 

4,  5.  Upper  and  dorsal  views  of  a  small  specimen. 
6.  Upper  view  of  a  partially  exfoliated  specimen. 
New  Scotland  formation,  New  York. 

Fig.  7.     PLATYCERAS  PLATYSTOMUM  Hall 477 

View  of  the  right  side  of  a  specimen,  the  apex  of  which  is  broken 
off.    New  Scotland  formation,  New  York. 

Figs.  8,  9.     PLATYCERAS    SPIRALE   Hall 478 

Views  of  internal  cast.     Helderberg  formation,  New  Scotland  mem- 
ber, Corriganville. 

Figs.  10-13.     PLATYCERAS  GRACILE  Ohern  n.  sp 478 

10. 12.  Two  views  of  individual  without  plications. 

11. 13.  Views  of  strongly  plicate  specimen. 

Oriskany  formation,  Ridgely  member,  Cumberland. 


70 


MARYLAND    GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,  PLATE  LXXXV 


11  12 

MOLLUSCA — GASTROPODA 


PLATE  LXXXVI 

PAGE 

Figs.  1-3.     PLATYCERAS  SUBCONICUM  Ohern  n.  sp 479 

1,  2.  Views  of  type. 

3.  Individual  with  low  folds. 

Oriskany  formation,  Ridgely  member,  Cumberland. 

Fig.  4.     PLATYCERAS  NEWBERRYI  Hall 479 

Side  view.    Oriskany  formation,  Ridgely  member,  Warren  Point,  Penna. 

Figs.  5-7.     STROPHOSTYLUS  TRAXSVERSUS  Hall 480 

Upper,  ventral,  and  oblique  views.    Oriskany  formation,  Ridgely  mem- 
ber, Cumberland.    ( After  Hall. ) 

Figs.  8,  9.     STROPHOSTYLUS   MATHERI  Hall 481 

Dorsal  and  ventral  views.    Oriskany  formation,  Ridgely  member,  Cum- 
berland.   (After  Hall.) 

Fig.  10.     STROPHOSTYLUS  ANDREWSI  Hall 481 

Ventral  view.     Oriskany  formation,   Ridgely   member,   Cumberland. 
(After  Hall.) 

FigS.    11,    12.      DlAPHOROSTOMA  DEPRESSUM    (Hall) 482 

Lower  and  dorsal  views.    New  Scotland  formation,  New  York. 

Figs.  13,  14.     DIAPHOROSTOMA  DESMATUM  Clarke 483 

Upper  and  ventral  views.    Oriskany  formation,  New  York. 


77 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,   PLATE  LXXXVI 


13 


t  K^^k. 


14 


6 

MOLLUSCA — GASTROPODA 


PLATE  LXXXVII 

PAGE 

Figs.  1,  2.     DIAPHOROSTOMA  vENTRicosvM   (Conrad) 482 

Dorsal  and  ventral  views  of  a  large  individual.    Oriskany  formation, 
Ridgely  member,  Cumberland. 

Figs.  3,  4.     PLATYSTOMA  NIAGARENSE  Hall 483 

Ventral  and   dorsal  views.     Helderberg  formation,  Keyser  member, 
Keyser,  W.  Va. 

Fig.  5.     TENTACULITES    ?  ACUS  Clarke 484 

Partially  exfoliated  specimen.    Oriskany  formation,  New  York. 

Figs.  6,  7.     TENTACULITES  ACULUS  Hall 485 

6.  Specimen  from  the  Helderberg  formation.  New  York. 

7.  Same.    X  5. 

Figs.  8-10.     TENTACULITES  ELONGATUS  Hall 485 

8.  An  individual  of  medium  size. 

9.  An  exfoliated  individual. 

10.  A  portion  of  the  same  enlarged,  showing  the  appearance  of  the  annu- 
lations.    X  4. 
New  Scotland  formation,  New  York. 

Fig.  11.     TENTACULITES  GYRACANTHUS    (Eaton) 486 

A  shell.    X  5.    Helderberg  formation,  Keyser  member,  Keyser,  W.  Va. 


78 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER  DEVONIAN,  PLATE  LXXXVII 


MOLLUSCA — GASTROPODA 


PLATE  LXXXVIII 

PAGE 

Figs.  1-3.     OKTHOCERAS  LONGICAMERATUM  Hall 487 

1.  Longitudinal  section  showing  curvature  of  septa. 

2.  Internal  cast,  doubtfully  referred  to  this  species. 

Helderberg  formation,  Cumberland. 

3.  A  longitudinal  section  of  a  specimen,  the  septa  being  proportionally 

a  little  more  distant.    Coeymans  formation,  New  York. 

Fig.  4.     OKTHOCERAS  SCHUCHERTI  Maynard  n.  sp 487 

Internal  cast.    Helderberg  formation,  Keyser  member,  Cumberland. 

Fig.  5.     ORTHOCERAS  RIGIDUM  Hall  ? 488 

Fragment  preserving  surface  ornamentation.     Helderberg  formation, 
Keyser  member,  Devil's  Backbone. 

Fig.  6.     CYRTOCERAS  ?  DUBIUM  Swartz  n.  sp 488 

Internal   cast   of  type.     Helderberg   formation,   Coeymans   member, 
Devil's  Backbone. 


79 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,   PLATE  LXXXVIII 


MOLLUSCA — CEPHALOPODA 


PLATE  LXXXIX 

PAGE} 

Fig.  1.     PROETUS  PACHYDERMATUS  Barrett 489 

Portion  of  cephalon  preserving  glabella.     X  2.    Helderberg  formation, 
Keyser  member,  Cumberland. 

Figs.  2-4.     PROETUS  CF.  PROTUBERANS  Hall 490 

2.  Cephalon. 

3.  The  pygidium  of  another  individual. 

4.  Profile  of  the  same. 

Coeymans  formation,  New  York. 

Figs.  5,  6.     CORDANIA  CYCLURUS  Hall  and  Clarke 491 

5.  Fragment  of  cephalon  showing  lateral  furrows  of  the  glabella  a 

little  too  strongly.     X  3. 

6.  Pygidium  showing  ornamentation.    X  3. 

New  Scotland  formation,  New  York. 

Figs.  7,  8.     CYATHASPIS  AUSTRALIS  Ohern  n.  sp 492 

Two  views  of  the  type.    X  3.    Helderberg  formation,  Cumberland. 

Fig.  9.     CALYMENE  CAMERATA  Conrad 494 

Pygidium,  exfoliated.    Helderberg  formation,  Keyser  member,  Pinto. 

Figs.  10-12.     HOMALONOTUS  SWARTZI  Ohern  n.  sp 495 

10, 11.  Detached  pleura?. 
12.  Glabella. 

Oriskany  formation,  Ridgely  member,  Millers  Spring  near 
Cumberland. 

Figs.  13-15.     HOMALONOTUS  VANUXEMI  Hall 496 

13, 14.  Views  of  pygidium. 
15.  Nearly  complete  cephalon. 

Oriskany  formation,  Ridgely  member,  Franklin,  W.  Va. 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER  DEVONIAN,   PLATE  LXXXIX 


ARTHROPODA— TRILOBITA 


PLATE  XC 

PAGE 

Figs.  1,  2.     HOMALONOTUS  sWARTZi  Ohern  n.  sp 495 

Pygidium  of  type.     Oriskany  formation,  Ridgely  member,  Berkeley 
Springs,  W.  Va. 

Fig.  3.     HOMALONOTUS  VANUXEMI  Hall 496 

Complete  cephalon.    Oriskany  formation,  Ridgely  member,  Franklin, 
W.  Va. 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,   PLATE  XC 


ARTHROPODA — TRILOBITA 


PLATE  XCI 

PAGE 

Figs.  1-4.     PHACOPS  LOGANI  Hall 497 

1.  An  entire  specimen  which  has  the  head  compressed  from  above,  and 

the  eyes  slightly  distorted. 

2.  The  head  of  a  larger  individual  which  shows  the  transverse  furrows* 

and  preserves  the  eyes  in  their  proper  form. 

3.  View  of  the  lower  side  of  the  head  of  another  specimen,  showing 

some  crenulations  along  the  marginal  furrow. 

4.  The  eye  enlarged. 

New  Scotland  formation,  New  York. 

Figs.  5-7.     PHACOPS    ?  sp 498 

5.  Cephalon  exfoliated. 
6,7.  Pygidia. 

Oriskany  formation,  Ridgely  member,  Cumberland. 

Figs.  8,  9.     DALMANITES  KEYSERENSIS  Swartz  n.  sp 499 

8.  Cephalon  of  the  type. 

9.  Part  of  a  pygidium  probably  belonging  to  the  same  species. 

Helderberg  formation,  Keyser  member,  Tonoloway. 

Figs.  10-11.     DALMANITES  MICRURUS    (Green) 507 

10.  A  small  pygidium. 

11.  A  larger  pygidium  from  which  the  test  has  been  removed,  leaving 

the  cast  punctate. 
New  Scotland  formation,  New  York. 

Figs.  12-15.     DALMANITES  MULTIANNULATUS  Ohern  n.  sp 500 

12.  Fragments  of  cheeks. 

13.  Glabella. 

14.  Eye  and  part  of  cheek. 

15.  Genal  angle. 

Oriskany  formation,  Knobly  Mountain,  near  Cumberland. 

Fig.  16.     DALMANITES  ASPINOSUS  Weller 499 

Exfoliated  pygidium.     Helderberg  formation,  Keyser  member,  Cash 
Valley. 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER  DEVONIAN,  PLATE  XCI 


13 


ARTHROPODA — TRILOBITA 


PLATE  XCII 

PAGE 

Figs.  1-4.     DALMAMTKS  MULTIANXULATUS  Ohern  n.  sp 500 

1.  Exfoliated  pygidium  showing  ornamentation  imperfectly. 

2.  Exfoliated  pygidium  which  does  not  show  the  tubercular  surface. 

3.  Hypostoma  showing  the  bifurcating  frontal  process. 

4.  Genal  angle. 

Oriskany  formation,  Ridgely  member,  Knobly  Mountain  near 
Cumberland. 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,   PLATE  XCII 


ARTHROPODA TRILOBITA 


11 


PLATE  XCIII 

PAGE 

Fig.  1.     DALMAXITES  MULTIANNULATUS  Ohern  n.  sp 500 

Fragment  of  an  exfoliated  pygidium.     Oriskany  formation,  Ridgely 
member,  Knobly  Mountain,  near  Cumberland. 

Fig.  2.     DALMANITES  LATUS  Ohern  n.  sp , 502 

Imperfect  pygidium  of  type.     Oriskany  formation,  Ridgely  member, 
Cumberland. 

Fig.  3.     DALMANITES  (SYNPHORIA)  STEMMATUS  Clarke 503 

Exfoliated  cephalon.    Oriskany  formation,  Ridgely  member,  Cumber- 
land. 

Fig.  4.     DALMANITES  (CORYCEPHALUS)  DENTATUS  Barrett  ? 505 

Pygidium.    Oriskany  formation,  Ridgely  member,  Evick  Gap  opposite 
Franklin,  W.  Va. 

Fig.  5.     DALMANITES  (CHASMOPS)  ANCHIOPS  (Green) 508 

Pygidium.    Oriskany  formation,  Ridgely  member. 

Figs.  6-10.     DALMANITES  (HAUSMANNIA)  PLEUROPTYX  (Green) 510 

6.  Imperfect  pygidium.    Helderberg  formation,  New  Scotland  member, 

Devil's  Backbone. 

7.  Young  specimen  enlarged  showing  the  characteristic  features  of 

species. 

8.  Profile  of  the  head,  showing  the  form  and  elevation  of  the  eye. 

9.  Exfoliated  glabella,  genal  angles  restored. 
10.  A  large  exfoliated  pygidium. 

New  Scotland  formation,  New  York. 


84 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,  PLATE  XCIII 


10 


ARTHROPODA — TRILOBITA 


PLATE  XCIV 

PAGE 

Fig.  1.     DALMAXITES  BEKKELEYENSIS  Swartz  n.  sp 512 

Pygidium  of  type  specimen.    Oriskany  formation,  Ridgely  member,  3 
miles  north  of  Berkeley  Springs,  W.  Va. 


85 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,   PLATE  XCIV 


ARTHROPODA — TRILOBITA 


PLATE  XCV 

PAGE 

Figs.  1-3.     APARCHITES  GORDON:  Ulrich  and  Bassler  n.  sp 515 

1.  Lateral  view  of  left  valve.    X  20. 

2,  3.  Longitudinal  and  vertical  sections  of  same.    X  20. 

Helderberg  formation,  Keyser  member,  Cumberland. 

Fig.  4.     PRIMITIA  POSTTURGIDA  Ulrich  and  Bassler  n.  sp 515 

The  unique  right  valve  on  which  this  species  is  founded,  showing  the 
flattened  anterior  spine  and  the  posterior  marginal  swelling. 
X  20.  Oriskany  formation,  21st  Bridge. 

Fig.  5,     PRIMITIA  ?  CUMBERLANDICA  Ulrich  and  Bassler  n.  sp 516 

A  left  valve  showing  the  subcentral  pit,  strongly  reticulated  surface 
and  elevated  rim.  X  20.  Helderberg  formation,  Keyser  mem- 
ber, Cumberland. 

Figs.  6-8.     PRIMITIA  ?  CONCENTRICA  Ulrich  and  Bassler  n.  sp 517 

Lateral,  dorsal,  and  anterior  views  of  a  right  valve.  X  20.  Oriskany 
formation,  21st  Bridge. 

Figs.  9,  10.     PRIMITIELLA  VARIOLATA  Ulrich  and  Bassler  n.  sp 518 

Lateral  and  dorsal  edge  views  of  a  right  valve.  X  20.  Oriskany  forma- 
tion, 21st  Bridge. 

Fig.  11.     ULRICHIA  A:QUALIS  Ulrich  and  Bassler  n.  sp 518 

Right  valve  showing  the  usual  form  and  obscure  surface  reticulation. 
X  20.  Oriskany  formation,  21st  Bridge. 

Figs.  12-15.     STREPULA  IRREGULARIS  Jones  and  Holl 519 

12.  An  incomplete  large  left  valve.    X  20. 

13, 14.  Two  right  valves  of  the  average  size  showing  differences  in  the 

surface  ornament  and  outline.     X  20. 
15.  Ventral  edge  view  of  original  of  fig.  13.    X  20. 

Fig.  16.     HALLIELLA  ?  SEMINULUM  VAR.  LONGA  Ulrich  and  Bassler  n.  var. . .   520 
A  right  valve  slightly  injured  along  the  margin.     X  20.     Helderberg 
formation,  Keyser  member,  Cumberland. 

Figs.  17,  18.     HALLIELLA  ?  TRIPLICATA  Ulrich  and  Bassler  n.  sp 521 

17.  Right  valve.     X  20. 

18.  End  view  of  same.    X  20. 

Helderberg  formation,  Keyser  member,  Cumberland. 

Figs.  19-21.     JECHMINA  CUSPIDATA  Jones  and  Holl 521 

19.  Left  valve  showing  the  extraordinary  development  of  the  spine. 

X  20. 

20.  21.  Lateral  and  anterior  end  views  of  a  right  valve.    The  variation 

shown  in  outline  of  body  of  valve  is  probably  due  to  accident. 
X  20. 
Helderberg  formation,  New  Scotland  member,  21st  Bridge. 

Figs.  22-24.     MESOMPHALUS  HARTLEYI  Ulrich  and  Bassler  n.  gen.  and  sp. . .   523 

22.  Lateral  view  of  right  valve  showing  the  ventral  swelling.     X  20. 

23.  An  average  right  valve  without  the  ventral  pouch.    X  20. 

24.  Left  valve  of  a  rather  small  complete  carapace.     X  20. 

Helderberg  formation,  Keyser  member,  Cumberland. 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER  DEVONIAN,  PLATE  XCV 


10 


15 


18 


ARTHROPODA — OSTRACODA 


PLATE  XCVI 

PAGE 

Figs.  1-3.     MESOMPHALUS  HARTLEYI  Ulrich  and  Bassler  n.  gen.  and  sp 523 

1,  2.  Ventral  and  posterior  end  views  of  a  female  individual.     X  20. 
3.  Highly  magnified  view  of  the  surface  of  original  of  fig.  24,  pi.  xcv. 

Figs.  4,  5.     MESOMPHALUS  SUBMARGINATA  Ulrich  and  Bassler  n.  sp 523 

Lateral  and  ventral  edge  views  of  the  type  specimen.     X  20.    Helder- 
berg  formation,  Keyser  member,  Cumberland. 

Figs.  6-9.     CTENOBOLBINA  ?  DENTICULATA  Ulrich  and  Bassler  n.  sp 524 

6.  Lateral  view  of  one  of  the  type  specimens,  a  left  valve  with  a  portion 

of  the  flange  broken  away  and  the  surface  simply  granulose. 
X  20. 

7.  Dorsal  edge  view  of  the  same  specimen.    X  20. 

8.  A  right  valve  showing  pits  between  the  granules  of  the  surface. 

X  20. 

9.  Ventral  edge  view  of  same.    X  20. 

Helderberg  formation,  Keyser  member,  Cumberland. 

Figs.  10-12.     CTENOBOLBINA  ?  DUBIA  Ulrich  and  Bassler  n.  sp 525 

10.  Left  side  of  complete  carapace.    X  20. 

11, 12.  Ventral  and  posterior  edge  view  of  same.    X  20. 

Helderberg  formation,  Keyser  member,  Cumberland. 

Figs.  13-15.     BOLLIA  AMERICANA  Ulrich  and  Bassler  n.  sp 525 

Lateral,  ventral  and  posterior  views  of  a  left  valve.     X  20.    Oriskany 
formation,  21st  Bridge. 

Figs.  16,  17.     BOLLIA  CURTA  Ulrich  and  Bassler  n.  sp 526 

Side  and  ventral  views  of  a  left  valve  of  this  well-marked  species. 
X  20.    Oriskany  formation  21st  Bridge. 

Fig.  18.     BOLLIA  IRREGULARIS  Ulrich  and  Bassler  n.  sp 527 

Lateral  view  of  right  valve.     X  20.    Helderberg  formation,  New  Scot- 
land member,  21st  Bridge. 

Fig.  19.     BOLLIA  JUGALIS  Ulrich  and  Bassler  n.  sp 527 

A  left  valve  showing  the  ventral  coalescence  of  the  median  and  mar- 
ginal ridges.     X  20.    Oriskany  formation,  21st  Bridge. 

Figs.  20-22.     BOLLIA  UNGULA  Jones 528 

Lateral,  ventral  and  posterior  views  of  a  left  valve.     X  20.     Oriskany 
formation,  21st  Bridge. 


87 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER  DEVONIAN,  PLATE  XCVI 


14 


17 


18 


21 


22 


ARTHROPODA — OSTRACODA 


PLATE  XCVII1 

PAGE 

Figs.  1-4.     KLCEDENIA  CENTRICORNIS  Ulrich  and  Bassler 529 

1.  Lateral  view  of  left  valve  (female  individual)  broken  anteriorly. 

X  20. 

2.  Left  valve  of  a  complete  carapace.    X  20. 

3.  4.  Posterior  and  ventral  views  of  same  specimen.    X  20. 

Figs.  5-7.     KLCEDENIA  FIMBRIATA  Ulrich  and  Bassler 529 

5.  Lateral  view  of  a  perfect  left  valve.    X  20. 

6,  7.  Ventral  and  end  views  of  same  specimen.    X  20. 

Coeymans  formation,  Herkimer  County,  New  York. 

Figs.  8,  9.     LEPEKDITIA  ALTOIOES  Weller 513 

8.  Left  valve.    X  2^. 

9.  Right  valve.    X  2%. 

Decker  Ferry  formation,  Flatbrookville,  New  Jersey. 

Fig.  10.     LEPERDITIA  GIGANTEA  Weller 514 

A  left  valve,  natural  size.    Rondout  formation,  Nearpass  Quarry,  New 
Jersey. 

Fig.  11.     LEPERDITIA  ELONGATA  Weller 514 

A  right   valve.      X  2.     Rondout   formation,   Nearpass   Quarry,   New 
Jersey. 

Figs.  12,  13.     KLCEDENIA  NEARPASSI   (Weller) 530 

Left  and  right  valves.   X  6.  Decker  Ferry  formation,  Nearpass  Quarry, 
New  Jersey. 

Figs.  14,  15.     KLCKDENIA  SUSSEXENSIS   (Weller) 532 

Two  left  valves  showing  slight  variations.     X  4  and   X  6.     Decker 
Ferry  formation,  Nearpass  Quarry,  New  Jersey. 

Fig.  16.     KLCEDENIA  KUMMELI   (Weller) 531 

A  left  valve.    X  3.    Rondout  formation,  Nearpass  Quarry,  New  Jersey. 

Fig.  17.     KLCEDENIA   BARRETTI    (Weller) 532 

A  right  valve.     X  5.    Decker  Ferry  formation,  Nearpass  Quarry,  New 
Jersey. 

Figs.  18-20.     KLCEDENELLA  PENNSYLVANIA  (Jones) 533 

Left  side,  end  and  ventral  views  of  a  complete  carapace.    X  15.    Helder- 
berg  formation,  Pennsylvania. 

Fig.  21.     KLCEDENELLA  CLARKEI   (Jones) 533 

Right  valve.     X  20.     Helderberg  formation,  Herkimer  County,  New 
York. 


'Figs.  8-17  (after  Weller),  Figs.  18-21  (after  Jones). 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER  DEVONIAN,   PLATE  XCVII 


12 


13 


16 


14 


15 


17 


20 


11 


ARTHROPODA — OSTRACODA 


PAGE 

Figs.  1-3.     KIXEDENELLA  cLARKEi  VAB.  PAUPERA  Ulrich  and  Bassler 534 

1.  Left  side  of  complete  carapace  showing  the  emaciated  appearance 

and  the  granules  in  some  of  the  furrows. 

2,  3.  Ventral  and  anterior  end  views  of  same. 

Helderberg  formation,  Keyser  member,  Cumberland. 

Figs.  4-6.     KLCEDENELLA  TUKGIDA  Ulrich  and  Bassler 535 

4.  Right  valve  of  an  unusually  short  specimen.     X  20. 

5,  6.  Left  and  right  valves  of  an  average  specimen.     X  20. 

Helderberg  formation,  Keyser  member,  Cumberland. 

Fig.  7.     KLCEDENELLA  TUKGIDA  VAR.  VENTROSA  Ulrich  and  Bassler 535 

Left  valve  of  a  complete  carapace.  X  20.  Helderberg  formation, 
Keyser  member,  Cumberland. 

Fig.  8.     THLIPSURA  MTILTIPUNCTATA  Ulrich  and  Bassler  n.  sp 536 

Lateral  view  of  right  valve.    X  20.    Oriskany  formation,  21st  Bridge. 

Figs.  9-11.     OCTONARIA  ?  ANGULATA  Ulrich  and  Bassler  n.  sp 537 

Two  right  and  a  left  valve  showing  slight  variations  in  outline  and 
markings.  X  20.  Helderberg  formation,  Keyser  member,  Cum- 
berland. 

Figs.  12-18.     OCTONARIA  IN.EQUALIS  Ulrich  and  Bassler  n.  sp 538 

12-14.  Left  side  and  posterior  and  ventral  views  of  a  complete  carapace. 
X  20. 

15.  Right  side  of  another  specimen  more  elongate  than  usual,  showing 

the  relatively  small  size  and  different  pitting  of  the  right  valve 
as  compared  with  the  left  valve.     X  20. 

16.  Left  valve  of  a  somewhat  shorter  form  in  which  the  two  lower  pits 

are  confluent.     X  20. 
17, 18.  Longitudinal  and  ventral  sections  of  same.     X  20. 

Helderberg  formation,  Keyser  member,  Cumberland. 

Fig.  19.     OCTONARIA  SIMPLEX  (Krause) 538 

Left  valve.  X  20.  Helderberg  formation,  Keyser  member,  Cumber- 
land. 

Fig.  20.     CRATERELLINA  OBLONGA  Ulrich  and  Bassler  n.  sp 540 

Right  valve  showing  the  crater-like  anterior  pit  and  the  somewhat 
irregular  shape  pertaining  to  this  species.  X  20.  Oriskany 
formation,  21st  Bridge. 

Fig.  21.     CRATERELLINA  ROBUSTA  Ulrich  and  Bassler  n.  sp 539 

A  characteristic  right  valve  of  this  large  and  well  marked  species. 
X  20.  Oriskany  formation,  21st  Bridge. 

Fig.  22.     BYTHOCYPRIS  PUNCTULATA  VAR.  ARCTATUM  Ulrich  and  Bassler  n. 

var 540 

Lateral  view  of  left  valve.  X  20.  Helderberg  formation,  Keyser 
member,  Cumberland. 

Figs.  23-25.     PONTOCYPRIS  ARCUATA  Ulrich  and  Bassler  n.  sp 541 

23.  Right  side  of  a  complete  carapace.     X  20. 

24,  25.  Dorsal  outline  and  posterior  end  view  of  same  specimen.     X  20. 

Helderberg  formation,  Keyser  member,  Cumberland. 

Figs.  26-28.     PONTOCYPRIS  MAWII  VAR.  BREVIATA  Jones 541 

26.  Left  valve.     X  20. 

27.  Outline  from  the  dorsal  side.    X  20. 

28.  Anterior  outline  view,  showing  dorsal  overlap  of  the  right  valve 

and  ventral  overlap  of  the  left. 

Helderberg  formation,  Keyser  member,  Cumberland. 

Figs.  29-31.     PACHYDOMELLA  LONGULA  Ulrich  and  Bassler  n.  sp 542 

29.  Right  valve.     X  20. 

30.  31.  Ventral  and  posterior  end  views  of  same.    X  20. 

Helderberg  formation,  Keyser  member,  Cumberland. 


MARYLAND  GEOLOGICAL  SURVEY 


LOWER   DEVONIAN,   PLATE  XCVIII 


14 


i 

19 


27 


10 


15 


20 


24 


11 


16 


25 


12 


17 


13 


18 


29  30 

ARTHROPODA OSTRACODA 


DEVONIAN 

MIDDLE 


NOTE 

Plates  I  to  VI,  illustrating  the  Geological  and  Paleontological  Relations  of 
the  Middle  and  Upper  Devonian,  are  bound  with  the  text  volume.  The  follow- 
ing plates  (Plates  VII  to  XLIV)  illustrate  the  Systematic  Paleontology  of  the 
Middle  Devonian  of  Maryland. 


12 


PLATE  VII 

PAGE 

Fig.  1.     STEREOLASMA  RECTUM    (Hall) 119 

Upright  view  of  corallum.  X  l1/^.  Romney  formation,  Hamilton  mem- 
ber, Ernstville. 

Fig.  2.     CF.  AMPLEXUS  HAMILTONI^,  Hall 120 

Upright  view  of  corallum.  Romney  formation,  Hamilton  member, 
Evitts  Creek. 

Fig.  3.     HELIOPHYLLUM  sp 121 

Upright  view  of  part  of  corallum,  epitheca  partly  exfoliated  showing 
the  septa.  X  l1^.  Romney  formation,  Hamilton  member, 
Ernstville. 

Figs.  4,  5.     CYSTIPHYLLUM  AMERICANTJM  Milne-Edwards  and  Haime  (?)..   121 

4.  Upright  view  of  corallum. 

5.  Transverse  section  of  the  same. 

Romney  formation,  Hamilton  member,  Evitts  Creek. 

Fig.  6.     POLYGNATHUS  sp.  undet 122 

Incomplete  jaw.  The  tips  of  four  or  five  teeth  which  were  discernible 
on  the  specimen  are  not  brought  out  in  the  illustration.  Tonolo- 
way.  (After  Kindle.)  Romney  formation,  Onondaga  member. 

Figs.  7-9.     RHOPALONARIA  TENUIS  Ulrich  and  Bassler 123 

7,  8.  Two  small  portions  of  the  zoarium  which  on  account  of  the  fre- 
quent crossing  of  the  branches  do  not  show  the  characteristic 
pinnate  arrangement  of  the  rows  of  cells.     X  9. 
Romney  formation,  Hamilton  member,  Evitts  Creek. 

9.  View  of  one  of  the  type  specimens  of  this  species.     (After  Ulrich 

and  Bassler.)     Thedford,  Ont.     X  9. 

Figs.  10-12.     MONTICULIPORA  (?)  MARYLANDENSIS  Ulrich  and  Bassler  n.  sp. .   123 

10.  Vertical  section,  showing  tabulation.    X  20. 

11.  Tangential  section.     X  20. 

12.  Several  zorecia  of  same,  to  show  structure  of  walls  and  acantho- 

pores.    X  35. 

Romney  formation,  Hamilton  member,  Evitts  Creek. 


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PAGE 
FigS.    1-4.      LlNGULELLA    (?)    PALIFORMIS    Hall 124 

1.  Interior  of  dorsal  valve  (?).    Evitts  Creek. 

2.  Ventral  valve,  showing  faintly  the  pedicle-groove.     Evitts  Creek. 

x  iy2. 

3.  A  partly  exfoliated  valve.    Evitts  Creek.    X  1%. 

4.  Ventral  valve,  the  specimen  showing  the  pedicle-groove.    Williams 

Road,  3%  miles  southeast  of  Cumberland.    X  2. 
Romney  formation,  Hamilton  member. 

Pig.  5.     LINGULA  DELIA  Hall  (?) 125 

Ventral  valve  (?)   showing  strong  median  septum.     X  1%.     Romney 
formation,  Hamilton  member,  Evitts  Creek. 

Fig.  6.     LINGULA  LIGEA  Hall  (?) 126 

Interior    of    partly    exfoliated    valve.      X  2y2.      Romney    formation, 
Hamilton  member,  21st  Bridge. 

Figs.  7,  8.     LINGULA  CF.  NUDA  Hall 127 

7.  Partly  exfoliated  distorted  valve.    X  2y2.    Romney  formation,  Onon- 

daga  member,  Williams  Road,  3%  miles  southeast  of  Cumber- 
land. 

8.  Partly  exfoliated  ventral  valve   (?).     X  1%.     Romney  formation, 

Hamilton  member,  Oldtown  Road,  east  of  Cumberland. 

Figs.  9,  10.     LINGULA  NUDA  Hall 127 

Separate  valves  showing  the  usual  variety  of  form  in  this  species. 
Hamilton  formation,  New  York. 

Fig.  11.     LINGULA  CF.  COMPTA  Hall  and  Clarke 128 

View  of  crushed  and  broken  specimen.     X  1*4.     Romney  formation, 
Hamilton  member,  Evitts  Creek. 

Figs.  12,  13.     LINGULA  CLARKI  n.  sp 128 

Partly  exfoliated  valves  showing  strong  median  convexity.    X  3.    Rom- 
ney formation,  Hamilton  member,  21st  Bridge. 

Figs.  14-17.     ORBICULOIDEA  LODIENSIS  VAR.  MEDIA  (Hall) 129 

14.  Interior  of  dorsal  valve.    X  2. 

15.  Exterior  ventral  valve  showing  the  pedicle-groove.    X  2. 

Romney  formation,  Hamilton  member,  Evitts  Creek. 

16.  Interior  of  a  partly  exfoliated  ventral  valve.    The  more  exfoliated 

portions  are  smooth,  not  striated,  as  indicated  by  figure.    Bells 
Gap,  Va. 

17.  Natural  cast  of  the  exterior  of  ventral  valve,  showing  concentric 

striae.    East  of  Cumberland. 
Romney  formation,  Onondaga  member.    (After  Kindle.) 


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PAGE 

Figs.  1-7.     CRANIELLA  HAMILTOXM:  Hall 131 

1.  Internal  impression  of  dorsal  valve.     X  1%. 

2.  Upper  or  dorsal  valve  from  which  the  shell  is  gone  near  the  margin. 

X  2. 

3.  Enlargement  of  part  of  preceding  showing  the  finely  punctate  shell 

structure.    X  6. 
Romney  formation,  Hamilton  member,  Evitts  Creek. 

4.  Interior  of  a  lower  valve  attached  to  a  Streptelasma. 

5.  Three  individuals  of  different  sizes,   attached   to  the   surface  of 

Tropidoleptus  carinatus. 

6.  Dorsal  valve. 

7.  Internal  impression  of  dorsal  valve.    X  2. 

Hamilton  formation,  New  York. 

Fig.  8.     PHOLIDOPS   HAMILTONI.E   Hall 132 

Interior  of  valve.     X  8.    Romney  formation,  Onondaga  member,  Wil- 
liams Road,  3%  miles  southeast  of  Cumberland. 

Figs.  9,  10.     PHOLIDOPS  CF.  AREOLATA  (Hall) 133 

9.  Cast  of  the  ventral  valve. 

10.  Internal  cast  of  the  ventral  valve.  The  slender  impressed  median 
line  of  the  figure  has  about  twice  the  proper  length.  It  is  con- 
spicuous only  near  the  apex  of  the  crescent-shaped  depression. 
X5. 

Romney  formation,  Onondaga  member,  Bells  Valley,  Virginia. 
(After  Kindle.) 

Figs.  11-17.     STROPHEODONTA  (LEPTOSTROPHIA)  PERPLAXA  (Conrad) 134 

11.  Partly  exfoliated  interior  of  dorsal  valve.    Iron  Bridge  over  Town 

Creek,  northeast  of  Oldtown. 

12.  Apparently  exfoliated  interior  of  dorsal  valve,  same  locality. 

13.  Internal  impression  of  small  ventral  valve.    X  1%.  Williams  Road, 

%  mile  east  of  Queen  City  Hotel,  Cumberland. 

14.  Further  enlargement  of  preceding  specimen,  showing  crenulated 

hinge-line.     X  3. 

15.  Internal  impression  showing  median  ridge.   Iron  Bridge  over  Town 

Creek,  northeast  of  Oldtown. 

16.  Internal  impression  of  ventral  valve  showing  muscular  impres- 

sions.   McCoys  Ferry. 
Romney  formation,  Hamilton  member. 

17.  An  enlargement  of  the  striae.    Hamilton  formation,  New  York. 


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PLATE  X 

PAGE 

Fig.  1.     STROPHEODONTA  DEMISSA   (Conrad) 136 

Ventral  valve.    Romney  formation,  Hamilton  member,  Hancock-Har- 
risonville  Road,  about  2  miles  north  of  Hancock. 

Figs.  2-5.     STROPHEODONTA  (DOUVILLINA)  IN^QUISTRIATA  (Conrad) 138 

2.  Interior  of  ventral  valve,  showing  fragment  of  shell  near  lateral 

margin. 

3.  Enlargement  of  same,  showing  striae.     X  6. 

4.  Squeeze  of  No.  2. 

Romney  formation,  Hamilton  member,  Evitts  Creek. 

5.  Interior  of  ventral  valve.    Hamilton  formation,  New  York. 

Figs.  6,  7.     STROPHEODONTA  CONCAVA   Hall 139 

6.  Interior  of  dorsal  valve,  showing  its  strongly  pustulose  character 

and  part  of  crenulated  hinge-line.    Romney  formation,  Hamilton 
member,  Evitts  Creek. 

7.  Ventral  valve  which  is  carinate  along  the  center.    Hamilton  forma- 

tion, New  York. 

Figs.  8,  9.     PHOLIDOSTROPHIA  PENNSYLVANIA  Kindle 141 

8.  Ventral  valve  of  type.     X  3.    East  of  Cumberland. 

9.  Interior  of  ventral  valve,  showing  short  and  very  slender  median 

septum.    Berkeley  Springs,  W.  Va. 
Romney  formation,  Onondaga  member.     (After  Kindle.) 

Figs.  10,  11.     LEPT.ENA  RHOMBOIDALIS    (Wilckens) 141 

10.  Fragment  of  ventral  valve.    Romney  formation,  Hamilton  member, 

Ernstville. 

11.  View  of  dorsal  valve.    Hamilton  formation,  New  York. 


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PAGE 

Figs.  1-5.     LEPT/ENISCA  AUSTRALIS  Kindle 143 

1-3.  Ventral  valves.    Fig.  1X2.    Berkeley  Springs,  W.  Va. 

4.  Type  specimen,  ventral  valve.     X  2.    Berkeley  Springs,  W.  Va. 

5.  Interior  of  dorsal  valve.    New  Bloomfield,  Pa. 

Romney  formation,  Onondaga  member.    (After  Kindle.) 

Figs.  6-10.     SCHUCHEBTELLA  vARiABiLis  Prosser  n.  sp 144 

6.  Dorsal  valve  ( ?).    Williams  Road,  %  mile  east  of  Queen  City  Hotel, 

Cumberland. 

7.  Ventral  valve.    X  I1/!.    Same  locality. 

8.  Portion  of  same  enlarged  to  show  character  of  striae.    X  4. 

9.  Dorsal  valve  (?). 

10.  Portion  of  same  enlarged  to  show  regular  variation  in  strength  of 
radiating  striae.     X  4. 

Romney  formation,  Hamilton  member. 

Figs.  11-1 7.     CHONETES  MUCBONATUS  Hall 146 

11.  Ventral  valve.    X  2.    McCoys  Ferry. 

12.  Ventral  valve,  showing  two  spines  near  each  cardinal  angle.     X  2. 

Same  locality. 

13.  Partly  exfoliated  interior  of  ventral  valve,  showing  cardinal  spine. 

X  2.    Same  locality. 

14.  Interior  of  ventral  valve  showing  muscular  impressions  and  one 

cardinal  spine.     X  2.    Same  locality. 
Romney  formation,  Hamilton  member. 

15.  Dorsal  valve,  showing  cardinal  spines.     Hamilton  formation,  New 

York. 

16.  Small  pedicle  valve.    X  3.    Cumberland. 

17.  A  pedicle  valve  of  average  size  and  appearance,  showing  the  long 

spines.    X  2.    Cumberland. 
Romney  formation,  Onondaga  member.    (After  Kindle.) 

Figs.  18-21.     CHONETES  COBOXATUS  (Conrad) 148 

18.  Partly  exfoliated  ventral  valve,  showing  shallow  median  sinus  and 

cardinal  spines.    Evitts  Creek. 

19.  Interior  of  ventral  valve,  showing  pustulose  pittings  toward  margin 

of  shell.     Hancock-Harrisouville  Road,  about  2  miles  north  of 
Hancock. 

20.  Dorsal  valve.    Hancock-Harrisonville  Road,  about  2  miles  north  of 

Hancock. 

21.  Interior   of  ventral   valve   showing  pustulose   pittings.     McCoys 

Ferry. 
Romney  formation,  Hamilton  member. 

Figs.  22-25.     CHOXETES  SETIGER  (Hall) 152 

22.  Ventral  valve,  partly  exfoliated.     X  2.     Iron  Bridge  over  Town 

Creek,  northeast  of  Oldtown. 

23.  Dorsal  valve.    X  1%.    West  of  Tonoloway  Ridge. 

24.  Interior  of  ventral  valve,  showing  pustulose  pittings  toward  margin 

of  shell.     X  1%.    McCoys  Ferry. 

Romney  formation,  Hamilton  member. 

25.  Ventral  valve  showing  cardinal  spines.    X  2.    Hamilton  formation, 

New  York. 


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Figs.  1-8.     CHONETES  SCITULUS  Hall 150 

1.  Interior  of  ventral  valve.    X  l1/^.    21st  Bridge. 

2.  Ventral  valve.     X  1%.    Right  bank  of  Potomac  about  4  miles  south 

of  Cumberland. 

3.  Ventral  valve.    X  \Vz-    Same  locality. 

4.  Dorsal  valve  of  same  specimen,  showing  cardinal  area  and  spines  of 

ventral  valve.    X  1%. 

5.  Partly  exfoliated  dorsal  valve  (?).    X  1%.    Iron  Bridge  over  Town 

Creek  northeast  of  Oldtown. 

6.  Interior  of  ventral  valve.     X  21/i.    B.  &  O.  R.  R.  cut  opposite  Han- 

cock. 

7.  Dorsal  valve  (?).    X  1%.    McCoys  Ferry. 

Romney  formation,  Hamilton  member. 

8.  Dorsal   valve,   showing   cardinal   area   and    deltidium.     Hamilton 

formation,  New  York. 

Figs.  9-13.     CHOXETES  LEPIDUS  Hall 153 

9.  Ventral  valve  partly  exfoliated,  showing  two  cardinal  spines.    X  3. 
Evitts  Creek. 

10.  Valve  showing  three  cardinal  spines.     X  4.    Evitts  Creek. 

11.  Interior  of  dorsal  valve  (?).     X  3.    Iron  Bridge  over  Town  Creek, 

northeast  of  Oldtown. 

12.  Interior  of  ventral  valve,  showing  cardinal  teeth.     X  3.    West  of 

Tonoloway  Ridge. 

13.  Ventral  valve  (?).     X  3.    B.  &  0.  R.  R.  cut  opposite  Hancock. 

Romney  formation,  Hamilton  member. 

Figs.  14-21.     CHONETES  vicixus   (Castelnau) 155 

14.  Ventral  valve.    Evitts  Creek. 

15.  Portion  of  the  same  near  the  umbo,  showing  the  intercalation  of 

radiating  and  fine  concentric  striae.     X  8. 

16.  Partly  exfoliated  ventral  valve  showing  one  cardinal  spine.     X  1^4' 

Iron  Bridge  over  Town  Creek,  northeast  of  Oldtown. 

17.  Interior  of  ventral  valve.     X  11A.    McCoys  Ferry. 

18.  Interior   of   dorsal   valve.      X  2.     Hancock-Harrisonville   Road,    2 

miles  north  of  Hancock. 

19-20.  Exteriors  of  ventral  valves.     X  2.     Same  locality. 
21.  Interior  of  the  dorsal  valve.     X  3.    Same  locality. 
Romney  formation,  Hamilton  member. 


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Figs.  1-6.     CHONETES  MABYLANDICUS  Prosser  n.  sp 157 

1.  Partly  exfoliated  interior  of  dorsal  valve.    X  1V2.    21st  Bridge. 

2.  Interior  of  ventral  valve.     X  1%.     Same  locality. 

3.  Exterior  of  dorsal  valve.     X  1%.    Same  locality. 

4.  Portion  of  the  same  enlarged,  showing  the  bifurcating  striae  and  the 

radiating  thread-like  ones.    X  5. 

5.  Partly  exfoliated  interior  of  dorsal  valve.     X  2.    21st  Bridge. 

6.  Interior  of  ventral  valve,  showing  rounded  median  ridge.     X  1%. 

Same  locality. 
Romney  formation,  Hamilton  member. 

Figs.  7-9.     CHONETES  BUGOSTJS  Kindle 158 

7.  Exfoliated  ventral  valve,  showing  imperfectly  the  subtended  proc- 

esses of  the  mucronate  spines.     X  2. 

8.  Type,  showing  a  ventral  valve  with  the  peculiar  spines  attached 

latterly  to  the  hinge  line.     X  2. 

9.  Natural  mold  of  the  exterior  of  a  ventral  valve.     X  2. 

Romney  formation,  Onondaga  member,  3  miles  east  of  Cum- 
berland.    (After  Kindle.) 

FigS.    10-13.      ANOPLEA  NUCLEATA 159 

10, 11.  Casts  of  two  ventral  valves,  showing  two  types  of  medium  sep- 
tum, one  terminating  anteriorly  in  an  indistinct  Y-shaped  proc- 
ess. X  3. 

12.  Cardinal  view  of  natural  cast  of  pedicle  valve,  showing  filling  of 

oblique  cardinal  tubes.     X  5. 

13.  Pedicle  view. 

Romney  formation,  Onondaga  member,  Mendota,  Va.     ( After 
Kindle.) 

Figs.  14-16.     STROPHALOSIA  TKTJNCATA   (Hall) 160 

14.  Exfoliated  ventral  valve,  showing  truncated  umbo.     X  3.     Iron 

Bridge  over  Town  Creek,  northeast  of  Oldtown. 

15.  Part  of  an  exfoliated  ventral  valve.     X  4.    Same  locality. 

16.  Exfoliated  dorsal  valve.     X  2.    Evitts  Creek. 

Romney  formation,  Hamilton  member. 

Fig.  17.     PRODUCTEIXA  CF.  SPINULICOSTA  Hall 162 

Exfoliated  ventral  valve.  X  2.  Williams  Road.  */£  mile  east  of  Queen 
City  Hotel,  Cumberland.  Romney  formation,  Hamilton  member. 

Figs.  18-20.     PRODUCTELLA  SPINULICOSTA  Hall 162 

18.  Ventral  valve  of  a  small  broad  form. 

19.  Cardinal  view  of  ventral  valve. 

20.  Small   individual  imbedded   in  the  rock   and   showing  attached 

spines. 
Hamilton  formation,  New  York. 

Fig.  21.     PRODUCTELLA  ( ?)  SCHUCHERTI  Prosser  n.  sp 163 

Imperfect  ventral  valve.    Ernstville. 

Figs.  22-25.     DALMANELLA  LENTICULARIS    (Vanuxem) 164 

22.  Dorsal  view.     X  2. 

23.  Interior  of  a  dorsal  valve. 

24.  25.  Two  fragmentary  casts  of  ventral  valves. 

Romney  formation,  Onondaga  member,  Berkeley  Springs,  W 
Va.     (After  Kindle.) 

Figs.  26-29.     RHIPIDOMELLA  VANUXEMI  Hall 165 

26.  Ventral  valve.    Evitts  Creek. 

27.  Dorsal  valve  of  same  specimen. 

28.  Interior  of  dorsal  valve.     Williams  Road,  */£  mile  east  of  Queen 

City  Hotel,  Cumberland. 

Romney  formation,  Hamilton  member. 

29.  An  enlargement  of  the  surface  stria?.     Hamilton  formation,  New 

York. 


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Figs.  1-5.     RHIPIDOMELLA  LEUCOSIA  Hall 166 

1.  Interior  of  dorsal  valve.    Williams  Road,  %  mile  east  of  Queen  City 

Hotel,  Cumberland.    Romney  formation,  Hamilton  member. 

2.  Dorsal  valve  of  specimen  of  ordinary  size. 

3.  Ventral  valve  of  the  same. 

Hamilton  formation,  New  York. 

4.  Interior  of  dorsal  valve  showing  cardinal  process  and  dental  sockets. 

Little  Run,  near  Hancock. 

5.  Interior  of  ventral  valve  showing  muscle  scars.     Two  miles  north  of 

Hancock. 

Romney  formation,  Hamilton  member. 

Figs.  6-9.     RHIPIDOMELLA  PENELOPE  Hall 167 

6.  Broken  specimen   of  ventral  valve    (?).     Evitts   Creek.     Romney 

formation,  Hamilton  member. 

7.  Interior  of  dorsal  valve.    Cumberland. 

8.  Enlargement  of  surface,  showing  the  character  of  the  striae,  the 

ordinary  puncta  and  the  elongate  tubular  openings. 

9.  Interior  of  ventral  valve  showing  the  muscular  impressions  and 

cardinal  teeth. 

Hamilton  formation,  New  York. 

Fig.  10.     RHIPIDOMELLA  CYCLAS  Hall   (?) 169 

10.  External  impression  of  ventral  valve.    X  1%.    Williams  Road  near 

church,  S1/^  miles  southeast  of  Cumberland. 

Figs.  11,  12.     DALMAXELLA  LENTICULAKIS    (Vanuxem) 164 

11.  Dorsal  valve  (?).    X  l1^.    Ernstville. 

12.  External   impression   of   dorsal    valve.      X  l1/^.      Hanging   Rock, 

W.  Va. 

Romney  formation,  Onondaga  member. 

Figs.  13,  14.     SCHIZOPIIOEIA  STBIATULA  (Schlotheim)    (?) 170 

13.  Partly  exfoliated  ventral  valve.    Ernstville. 

14.  A    portion    of    the    lateral    margin    enlarged,    showing    punctate 

structure.     X  5. 

Romney  formation,  Hamilton  member. 

Figs.  15-17.     CAMAROTCECHIA  CONGREGATA  (Conrad) 171 

15.  Interior  of  dorsal  valve.    X  I1/!- 

16.  Interior  of  somewhat  distorted  small  dorsal  valve.     X  I1/*. 

17.  Partly  exfoliated  ventral  valve.     X  1%.     Run  at  eastern  end  of 

Hancock. 

Romney  formation,  Hamilton  member. 


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Figs.  1-3.     CAMABOTCECHIA  PROLIFICA  Hall 173 

1.  Exfoliated  ventral  valve.     X  1%.    Right  bank  of  Potomac,  about  4 

miles   south    of   Cumberland.     Romney    formation,    Hamilton 
member. 

2.  Ventral  valve  of  an  unusually  large  specimen. 

3.  Interior  of  dorsal  valve. 

Hamilton  formation,  New  York. 

Fig.  4.     CAMAROTCECHIA  SAPPHO  Hall 174 

Interior  of  ventral  valve.    Romney  formation,  Hamilton  member. 

Fig.  5.     CAMAROTCECHIA  sp 175 

Interior  of  ventral  valve.    X  l1^.    Flintstone  Creek  in  Gilpin.    Romney 
formation,  Hamilton  member. 

Figs.  6-8.     LIORHYNCHTJS  LIMITARE   (Vanuxem) 175 

6,  7.  Crushed  and  broken  dorsal  valves.     X  1%.    21st  Bridge. 
8.  Young  specimen  crushed.     X  3.    Same  locality. 
Romney  formation,  Marcellus  member. 

Figs.  9-12.     LIORHYXCHUS  LAURA    (Billings) 177 

9.  Somewhat  distorted  and  crushed  exfoliated  dorsal  valve.     X  1%. 
Williams  Road  near  church,  Sy2  miles  southeast  of  Cumberland. 

10.  Interior  of  dorsal  valve.     X  l1^.    Williams  Road  near  church,  3^5 

miles  southeast  of  Cumberland. 

Romney  formation,  Hamilton  member. 

11.  Dorsal  valve  of  typical  specimen. 

12.  Cardinal  view. 

Hamilton  formation,  New  York. 

Figs.  13-17.     LIORHYNCHUS  CF.  MYSIA 178 

13-15.  Dorsal,  ventral  and  side  view  of  shell  of  usual  size. 

16.  Dorsal  view  of  larger  specimen  with  duplicate  plications. 

17.  Dorsal  view  of  large  individual. 

Marcellus  formation,  New  York. 

Figs.  18-23.     EUNELLA  LINCKL^ENI  Hall 179 

18.  Interior  of  ventral  valve,  distorted  by  pressure.    Iron  Bridge  over 

Town  Creek  northeast  of  Oldtown. 

19.  Interior  of  dorsal  valve  of  same  specimen. 

20.  Interior  of  dorsal  valve.    Road  east  of  Pine  Hill,  about  4  miles 

north  of  Oldtown. 

21.  Partly  exfoliated  ventral  valve  of  same  specimen. 

22.  Enlargement  showing  shell  structure  of  same.    X  about  20. 

Romney  formation,  Hamilton  member. 

23.  Brachial  loop.    Hamilton  formation,  New  York. 


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MOLLUSCOIDEA — BRACHIOPODA 


PLATE  XVI 

PAGE 

Figs.  1-3.     CENTROXEIXA  CF.  OVATA  Hall 179 

Dorsal,  side  and  ventral  view  of  shell.     Onondaga  formation,  New 
York. 

Figs.  4-6.     ATRYPA  RETICULARIS   (Linn6) 183 

4.  Partly  exfoliated  ventral  valve  (?). 

5.  Dorsal  valve. 

6.  Ventral  valve. 

Romney  formation,  Hamilton  member,  Evitts  Creek. 

Figs.  7-14.     TROPIDOLEPTUS  CARINATUS    (Conrad) 181 

7.  8.  Ventral  and  dorsal  valves  of  large  specimen.    21st  Bridge. 

9, 10.  Ventral  and  dorsal  valves  of  medium  specimen.    Same  locality. 

11.  Surface  enlarged  showing  punct*.     X  4.    Evitts  Creek. 

12.  Exterior  of  ventral  valve. 

13, 14.  Interior  of  ventral  and  dorsal  valves.     X  2.     Near  Tonoloway 
Ridge,  Washington  County. 

Romney  formation,  Hamilton  member. 


MARYLAND  GEOLOGICAL  SURVEY 


MIDDLE  DEVONIAN,  PLATE  XVI 


12 


14 


is. 


MOLLUSCOIDEA — BRACHIOPODA 


PLATE  XVII 

PAGE 

Figs.  1-9.     CYRTINA  HAMILTOXEXSIS  Hall 185 

1.  Interior  of  ventral  valve  distorted  by  crushing.    McCoys  Ferry. 

2.  Cardinal  area  of  same,  showing  delthyrium. 

3.  Interior  of  dorsal  valve.    McCoys  Ferry. 

4.  Dorsal  valve.    McCoys  Ferry.     X  1%. 

5.  Enlarged  part  of  shell  showing  its  structure.     X  4.    National  Road 

northeast  of  Cumberland. 

6.  Cardinal  area  of  ventral  valve.     X  2.    Near  Hancock. 

7.  8.  Internal  casts  of  ventral  valve.    Near  Hancock. 

Romney  formation,  Hamilton  member. 

9.  Dorsal   valve   and   cardinal   area   of   ventral   valve,   showing   the 

elongate  foramen  on  the  deltidial  plate.     Hamilton  formation, 
New  York. 

Figs.  10-18.     SPIRIFEB  MUCRONATUS   (Conrad) 187 

10.  Ventral  valve.    Evitts  Creek. 

11.  Dorsal  valve  of  same. 

12.  Interior  of  ventral  valve.    Iron  Bridge  over  Town  Creek,  northeast 

of  Oldtown. 

13.  Interior  of  dorsal  valve.    Same  locality. 

14.  Interior  of  partly  exfoliated  dorsal  valve.    McCoys  Ferry. 
15-17.  Exteriors  of  ventral  valves.    Near  Hancock. 

18.  Interior  of  ventral  valve.    Near  Hancock. 

Romney  formation,  Hamilton  member. 


MARYLAND  GEOLOGICAL  SURVEY 


MIDDLE  DEVONIAN,   PLATE  XVII 


17  18 

MOLLUSCOIDEA — BRACK  IOPODA 


PLATE  XVIII 

PAGE 

Figs.  1-6.     SPIRIFER  GRANULOSUS  (Conrad) 190 

1.  Ventral  valve.    21st  Bridge. 

2.  Interior  of  ventral  valve.    Flintstone  Creek  in  Gilpin. 

3.  Interior  of  dorsal  valve  of  same  specimen. 

4.  Enlarged  portion  of  surface  from  sinus  of  ventral  valve,  showing 

the  small  granules.     X  2.    Evitts  Creek. 

5.  Same  more  highly  magnified.     X  8. 

Romney  formation,  Hamilton  member. 

6.  An  enlargement  of  the  surface,  showing  its  papillose  character. 

Hamilton  formation,  New  York. 

Figs.  7-9.     SPIRIFER   AUDACULUS    (Conrad) 192 

7.  Ventral  valve,  partly  exfoliated.    Evitts  Creek. 

8.  Interior  of  ventral  valve.    Warrior  Mountain,  east  of  Rush. 

9.  Interior  of  dorsal  valve  and  cardinal  area  of  ventral  valve.    West- 

ern Maryland. 

Romney  formation,  Hamilton  member. 

Fig.  10.     SPIRIFER  ACUMINATUS    (Conrad) 193 

Interior  of  broken  dorsal  valve.    McCoys  Ferry.    Romney  formation, 
Hamilton  member. 


101 


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i  i  i 
5 


MOLLUSCOIDEA — BRACHIOPODA 


PLATE  XIX 

PAGE 

Figs.  1-7.     SPIRIFEB  TULLIUS  Hall 195 

1.  Interior  of  ventral  valve.     Hancock-Harrisonville  Road,   about   2 

miles  north  of  Hancock. 

2.  Interior  of  small  ventral  valve.    X  l1/^.    Same  locality. 

3.  Exterior  of  ventral  valve.    Near  Hancock. 

4.  Interior  of  dorsal  valve.    Little  Run,  near  Hancock. 

5.  Cardinal  view  of  ventral  valve.    Near  Hancock. 

6.  Enlargement  of  same,  showing  fine  striae  on  sinus  and  plications. 

X  4i/2. 
Romney  formation,  Hamilton  member. 

7.  Dorsal  valve  of  average  specimen.    Hamilton  formation,  New  York. 

Figs.  8,  9.     SPIRIFER  ANGUSTUS  Hall 196 

8.  Cardinal  view  of  internal  cast.     Warrior  Mountain,  east  of  Rush. 

Romney  formation,  Hamilton  member. 

9.  Dorsal  valve  of  rather  large  individual.    Hamilton  formation,  New 

York. 

Figs.  10-12.     SPIRIFER  (RETICULARIA)  FIMBRIATUS  (Conrad) 197 

10.  Partly  exfoliated  dorsal  valve.    Evitts  Creek. 

11.  Cardinal  view  of  internal  cast.    Hardy  County,  W.  Va. 

12.  An  enlargement  of  the  surface,  showing  the  bases  of  the  spinules. 

Romney  formation,  Hamilton  member. 

Fig.  13.     SPIRIFER  CF.  COXSOBRIXUS  (d'Orbigny) 198 

Interior  of  ventral  valve.     Town  Creek,  6  miles  north  of  Oldtown. 
Romney  formation,  Hamilton  member. 

Figs.  14-16.     SPIRIFER  SCULPTILIS  VAR.  MARYLANDENSIS  Prosser  n.  var 200 

14.  Dorsal  valve.    Warrior  Mountain,  east  of  Rush. 

15.  Squeeze  of  same.    X  1%. 

16.  Internal  impression  of  same. 

Romney  formation,  Hamilton  member. 


102 


MARYLAND  GEOLOGICAL  SURVEY 


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15 


MOLLUSCOIDEA — BRACHIOPODA 


PLATE  XX 

PAGE 

Figs.  1,  2.     AMBOCCELIA  UMBOXATA  Conrad 200 

1.  Partly  exfoliated  ventral  valve.    X  2.    Ernstville. 

2.  Partly  exfoliated  dorsal  valve.     X  l1/^.    Evitts  Creek. 

Romney  formation,  Hamilton  member. 
Figs.  3-6.     AMBOCCELIA  VIRGINIAN  A  Prosser  n.  sp 202 

3.  Ventral  valve.     X  6.    3  miles  south  of  Green  Spring,  W.  Va.    Mar- 

cellus  limestone. 

4.  Ventral  valve.    X  5.    Right  bank  of  Potomac,  iyz  miles  below  Cum- 

berland. 

5.  Dorsal  valve  of  same  specimen.    X  5. 

6.  Cardinal  area  and  dorsal  valve  of  same  specimen,    x  5. 

Romney  formation,  Hamilton  member. 
Figs.  7,  8.     AMBOCCELIA  PR.EUMBONA  Hall  (?) 204 

7.  Partly  exfoliated  ventral  valve.    X  1%. 

8.  Interior  of  ventral  valve.    X  1^4.    Ernstville. 

Romney  formation,  Hamilton  member. 

Figs.  9-11.     AMBOCCELIA  PR^EUMBONA  Hall 204 

9.  Ventral  valve. 

10.  Dorsal  valve. 

11.  Profile  view. 

Hamilton  formation,  New  York. 
Figs.  12-15.     NUCLEOSPIRA  CONCINNA  Hall 206 

12.  Interior  of  ventral  valve  (?).    X  IVz- 

13.  Interior  of  ventral  valve.    X  l]/&. 

Romney  formation,  Hamilton  member,  Ernstville. 

14.  Ventral  valve. 

15.  A  portion  of  surface  enlarged,  showing  the  character  of  the  spin- 

ules. 

Hamilton  formation,  New  York. 
Figs.  16-23.     AXOPLOTHECA  (CcELospiRA)  AcuTiPLiCATA  (Conrad) 207 

16.  Ventral  valve.     X  1%.     Williams  Road  near  church,   3%    miles 

southeast  of  Cumberland. 

17.  Squeeze  of  same,  showing  appearance  of  ventral  valve.     X  I1/!. 

18.  Dorsal  valve.      X  1%.     Williams   Road   near   church,   3%    miles 

southeast  of  Cumberland. 

19.  Squeeze  of  same,  showing  appearance  of  dorsal  valve.     X  I1/*. 

20.  Interior  of  partly  exfoliated  dorsal  valve.     X  l1^-    Williams  Road, 

S1/^  miles  southeast  of  Cumberland. 

21.  Squeeze  of  same,  showing  appearance  of  dorsal  valve.     X  I1/!. 

22.  Squeeze  of  internal  impression  of  dorsal  valve,  showing  hinge- 

plate,  deep  dental  sockets  and  median  ridge.     X  1%.    Williams 
Road  near  church,  3%  miles  southeast  of  Cumberland. 

23.  Cast  of  a  dorsal  valve.    X  2.    East  of  Cumberland. 

Romney  formation,  Onondaga  member.   (Fig.  23  after  Kindle.) 

Fig.  24.     ANOPLOTHECA  CAMILLA    (Hall) 209 

View  of  pedicle  valve.     Romney  formation,  Onondaga  member,  Blair 

County,  Penna.     (After  Kindle.) 
Figs.  25,  26.     VITULINA  PUSTULOSA  Hall 210 

25.  Exfoliated  ventral  valve.     X  1%.     National  Road,  northeast  of 

Cumberland. 

26.  Enlargement  from  an  impression  of  the  surface,  showing  the  ap- 

pearance of  the  pustules.    X  4. 
Romney  formation,  Hamilton  member. 

103 


MARYLAND  GEOLOGICAL  SURVEY 


MIDDLE  DEVONIAN,   PLATE  XX 


OP      dl 

^f&  Jr 


10 


14 


11 


13 


15 


26 


MOLLUSCOIDEA — BRACHIOPODA 


PLATE  XXI 

PAGE 

Figs.  1,  2.     ATHYBIS  SPIRIFEROIDES  (Eaton) 211 

1.  Ventral  valve. 

2.  Interior  of  same,  showing  the  muscular  markings. 

Romney  formation,  Hamilton  member,  Evitts  Creek. 

Figs.  3,  4.     MERISTELLA    (?)    sp 213 

3.  Ventral  valve.     X  6. 

4.  Dorsal  valve  (?).    X  6. 

Romney  formation,  Hamilton  member,  Iron  Bridge  over  Town 
Creek,  northeast  of  Oldtown  (?). 

Figs.  5-7.     PHTHONIA  SECTIFROXS   (Conrad) 214 

5.  External  impression  anterior  end  of  left  valve.    Romney  formation, 

Hamilton  member,  Williams  Road  near  church,  3%  miles  south- 
east of  Cumberland. 

6.  A  large  left  valve  narrowed  by  compression. 

7.  A  large  right  valve,  showing  the  form  and  surface  characters. 

Hamilton  formation,  New  York. 

Figs.  8-10.     PROTHYRIS  LANCEOLATA  Hall 215 

8.  Right  valve.     X  1%.    Romney  formation,  Hamilton  member.    Right 

bank  of  Potomac,  about  3  miles  below  Cumberland. 
9, 10.  Right  and  left  valves.    Hamilton  formation,  New  York. 

Figs.  11-13.     ORTHOXOTA  UNDULATA  Conrad 216 

11.  View  of  broken  specimen,  showing  anterior  portion  of  both  valves. 

B.  &  O.  R.  R.  cut,  opposite  Hancock. 

12.  Right  valve.    McCoys  Ferry. 

Romney  formation,  Hamilton  member. 

13.  A  specimen  of  medium  size  preserving  both  valves.     Hamilton 

formation,  New  York. 


104 


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MIDDLE  DEVONIAN,   PLATE  XXI 


10 


MOLLUSCOIDEA — BRACHIOPODA  AND   MOLLUSCA — PELECYPODA 


PLATE  XXII 

PAGE 

Figs.  1,  2.     ORTHONOTA  (?)  PARVULA  Hall 217 

1.  Both  valves.     X  2. 

2.  Dorsal  view  of  same.    X  2. 

Romney  formation,  Hamilton  member,  Evitts  Creek. 

Fig.  3.     GRAMMYSIA  BISULCATA    (Conrad) 218 

Ventral  view  of  distorted  and  crushed  specimen,  showing  part  of  both 
valves.    Romney  formation,  Hamilton  member,  McCoys  Ferry. 

Figs.  4-10.     GRAMMYSIA  ARCUATA  (Conrad) 219 

4.  Anterior  end  of  right  valve.    McCoys  Ferry. 

5.  Posterior  end  of  left  valve  of  same  specimen. 

6.  7.  Cardinal  and  ventral  views  of  a  specimen  vertically  compressed. 

Pine  Hill,  5  miles  north  of  Oldtown. 
8.  Right  valve  distorted  by  vertical  pressure.     Town  Creek,  about  6 

miles  north  of  Oldtown. 

Romney  formation,  Hamilton  member. 
9, 10.  Right  and  left  valves.    Hamilton  formation,  New  York. 

Figs.  11,  12.     TELLIXOPSIS  SUBEMARGIXATA   (Conrad) 222 

11.  Left  valve.    Evitts  Creek. 

12.  Part  of  left  valve  showing  fine  radiating  striae.     Right  bank  of 

Potomac,  about  3  miles  below  Cumberland. 
Romney  formation,  Hamilton  member. 


105 


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12 


MOLLUSCA — PELECYPODA 


14 


PLATE  XXIII 

PAGE 

Figs.  1,  2.     GRAMMYSIA  CIRCULAKIS  Hall 220 

Right  and  left  valves  partly  exfoliated,  showing  muscular  scars  and 
pallial  line.    Hamilton  formation,  New  York. 

Fig.  3.     GRAMMYSIA  CIRCULARIS  (?)  Hall 220 

Left  valve.    Romney  formation,  Hamilton  member,  21st  Bridge. 

Fig.  4.     BUCHIOLA  HALLI  Clarke 225 

Left  valve  showing  the  conspicuous  concentric  ridges  on  the  plications. 
X  2.    Romney  formation,  Hamilton  member,  Evitts  Creek. 

Fig.  5.     PANENKA  CF.  DICHOTOMA  Hall 224 

View  of  a  fragmentary  right  valve.     Romney  formation,  Onondaga 
member,  Oldtown. 

Figs.  6-10.     NUCULA  CORBULIFORMIS  Hall 226 

6.  Right  valve.     X  1%.    Right  bank  of  Potomac  River,  about  3  miles 

below  Cumberland. 

7.  Left  valve  of  same. 

8.  Right  valve.    X  1%.    Same  locality. 

9.  Cardinal  view  of  internal  impression  showing  hinge  crenulations. 

X  l1/^.    Same  locality. 

10.  Right  valve  showing  varices  of  growth  and  concentric  striae.    Evitts 
Creek. 

Romney  formation,  Hamilton  member. 

Fig.  11.     PANENKA  CF.  MULTIRADIATA  Hall 225 

View  of  a  large  right  valve  showing  strong  radii.    Hamilton  formation, 
New  York. 


106 


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11 


MOLLUSCA — PELECYPODA 


PLATE  XXIV 

PAGE 

Fig.  1.     PAXEXKA  ALTERNATA  Hall 223 

View  of  a  large  right  valve  showing  strong  radii.    Oldtown.    Romney 
formation,  Onondaga  member. 

Figs.  2,  3.     PAXEXKA  OBSOLESCEXS  Kindle  n.  sp 224 

2.  View  of  right  valve  of  type.    Oldtown. 

3.  Fragmentary  right  valve.    Ridgeville,  W.  Va. 

Romney  formation,  Onondaga  member. 


107 


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MOLLUSCA — PELECYPODA 


PLATE  XXV 

PAGE 

Figs.  1-5.    NUCULA  BELLISTRIATA  (Conrad) 227 

1.  Right  valve.     X  1%. 

2.  Right  valve,  showing  concentric  striae  and  strong  varices  of  growth. 

xiy2. 

3.  Left  valve.     X  2. 

Romney  formation,  Hamilton  member,  Evitts  Creek. 

4.  Interior  of  right  valve,  showing  muscular  scars.     X  1%. 

5.  Cardinal  view  of  same.     X  l1/^. 

Romney  formation,  Hamilton  member,  Western  Maryland. 

Figs.  6-8.     NUCULA  LIRATA   (Conrad) 229 

6.  Left  valve,  distorted  somewhat  about  the  beak.    Romney  formation, 

Hamilton  member,  Evitts  Creek. 

7.  Right  valve. 

8.  Enlarged  surface  showing  strong  concentric  undulations  and  fine 

radiating  striae. 

Hamilton  formation,  New  York. 

Figs.  9,  10.     NUCULA  LIKATA  (Conrad)    (?) 229 

9.  Interior  of  left  valve,  showing  muscular  scars,  pallial  line  and 

hinge  crenulations.    X  1%. 

10.  Cardinal   view  of  same  specimen,   showing  muscular  scars  and 
hinge  crenulations.    X  l1^. 

Romney  formation,  Hamilton  member,  Western  Maryland. 

Figs.  11-16.     NUCULA  VARICOSA  Hall 230 

11, 12.  Right  and  left  valves.    X  l1^. 

13.  Left  valve,  showing  concentric  striae  and  varices  of  growth.    X  l1^. 

14.  Enlargement  from  same,  showing  the  character  of  the  concentric 

striae  and  varices  of  growth.     X  4. 

Romney  formation,  Hamilton  member,  Evitts  Creek. 
15, 16.  Right  and  left  valves.    Hamilton  formation,  New  York. 

Figs.  17-20.     NUCULITES  OBLOSGATTJS  Conrad 231 

17.  Left  valve  showing  fine  concentric  striae.    Evitts  Creek. 

18.  Small  left  valve  also  showing  fine  concentric  striae.     X  2.     Evitts 

Creek. 

19.  Interior  of  right  valve,  showing  crenulated  hinge  and  impression 

of  clavicular  ridge.    National  Road,  northeast  of  Cumberland. 

20.  Interior  of  right  valve  elongated  by  pressure.     Hill  in  West  Vir- 

ginia, 3  miles  south  of  Cumberland. 
Romney  formation.  Hamilton  member. 


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15 


MOLLUSCA — PELECYPODA 


PLATE  XXVI 

PAGE 

Figs.  1-5.     NUCULITES  TRIQUETEB  Conrad 232 

1.  Small  right  valve.    X  l1^.    Evitts  Creek. 

2.  Partly  exfoliated   right  valve.     X  l1^.     Right  bank  of  Potomac, 

about  3  miles  below  Cumberland. 

3.  Left  valve  of  same  specimen,   showing  impression   of  clavicular 

ridge.     X  1%. 

4.  Internal  impression  of  right  valve,  showing  clavicular  ridge.    X  l1^. 

Hill  in  West  Virginia,  about  3  miles  south  of  Cumberland. 

5.  Internal  impression  of  right  valve,  distorted  by  pressure,  showing 

impression  of  clavicular  ridge.    X  l^.    McCoys  Ferry. 
Romney  formation,  Hamilton  member. 

Fig.  6.     NUCULITES  GRABAUI  Prosser  n.  sp 234 

Internal   impression  of  right  valve,  showing  impression   of   strong 
clavicular  ridge.     X  1%.     McCoys  Ferry.     Romney  formation, 
Hamilton  member. 
Figs.  7,  8.     NUCULITES  MODULATUS  Kindle 234 

7.  Type  specimen. 

8.  Another  individual. 

Romney  formation,   Onondaga  member,  Ridgeville,  W.   Va. 
(After  Kindle.) 

Figs.  9-12.     PALJEONEILO  CONSTRICTA  (Conrad) 235 

9.  Right  valve,  showing  crenulations  of  hinge-line,  fine  concentric 
striae  and  constriction.    X  la/4-    Evitts  Creek. 

10.  Right  valve  somewhat  elongated  by  pressure,  showing  crenulations 

of  hinge-line,  fine  striae  and  constriction.    X  1%.    Evitts  Creek. 

11.  Small  right  valve.    X  l1^.    Evitts  Creek. 

12.  Small  left  valve.     X  1%.    Williams  Road,  %  mile  east  of  Queen 
I  City  Hotel,  Cumberland. 

Romney  formation,  Hamilton  member. 
Figs.  13-15.     PAL^ONEILO  PLANA  Hall 237 

13.  Left  valve,  showing  hinge  crenulations.     X  1%.    Evitts  Creek. 

14.  Small    right   valve,   showing   hinge   crenulations.      X  2.      Evitts 

Creek. 

15.  Right  valve.      X  1%.     Right    bank   of   Potomac,   about   3   miles 

below  Cumberland. 

Romney  formation,  Hamilton  member. 

Fig.  16.     PAL^ONEILO  MAXIMA  (Conrad)    (?) 238 

Left  valve  with  strong  sulcus.     Romney  formation,  Hamilton  mem- 
ber, Evitts  Creek. 

Fig.  17.     PAL^ONEILO  MAXIMA   (Conrad) 238 

Right  valve  with  greater  height  than  usual.     Hamilton  formation, 

New  York. 
Figs.  18-21.     PAL^ONEILO  FECUNDA  Hall 239 

18.  Left  valve  showing  concentric  striae,    X  l1^,  and  above  that,   a 

portion  of  the  surface  bordering  the  hinge-line  enlarged  3  times. 
Williams  Road,  !/4  mile  east  of  Queen  City  Hotel,  Cumberland. 

19,  20.  Right  valves. 

21.  An  enlargement  of  the  surface  striae  from  fig.  20. 

Romney  formation,  Hamilton  member  (figs.  19-21  after  Hall). 
Figs.  22,  23.     PAL.EONEILO  PERPLANA  VAR.  GRABAUI  Prosser  n.  var 240 

22.  Squeeze  of  external  impression  of  right  valve. 

23.  Surface  of  same.    X  4. 

Romney  formation,  Hamilton  member,  Evitts  Creek. 

109 


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10 


11 


15 


12 


13 


16 


14 


17 


20 


22 


21 


23 


MOLLUSCA — PELECYPODA 


PLATE  XXVII 

PAGE 

Figs.  1-6.     PAL^ONEILO  EMARGINATA   (Conrad)    241 

1.  Left  valve,  showing  the  strong  concentric  ridges.    Evitts  Creek. 

2.  Left  valve  of  shorter  form.     Hancock-Harrisonville  Road,  about 

2  miles  north  of  Hancock. 

3.  Right  valve  of  same  specimen. 

4.  External  impression  of  right  valve.    McCoys  Ferry. 

Romney  formation,  Hamilton  member. 

5.  6.  Right  and  left  valves.     Hamilton  formation,  New  York. 

Fig.  7.     PAL^ONEILO  TENUISTRIATA  Hall   (?) 242 

Right  valve  of  a  broken  and  mostly  exfoliated  specimen.     Romney 
formation,  Hamilton  member,  McCoys  Ferry. 

Figs.  8,  9.     PAL^EONEILO  TENITISTRIATA  Hall 242 

Left  and  right  valves.     Romney  formation,  Hamilton  member,  near 
Cumberland.    (After  Hall.) 

Figs.  10-13.     PALVEOXEILO  CLARKEI  Prosser  n.  sp 244 

10.  Left  valve. 

11.  Broken  left  valve,  sinus  at  anterior  end  caused  by  crushing. 

12.  Right  valve,  shortened  by  the  breaking  away  of  the  posterior  end. 

13.  Interior  of  hinge  line  of  No.  12  enlarged,  showing  the  taxodont 

dentition.    X  2. 

Romney  formation,  Hamilton  member,  right  bank  of  Potomac 
River,  about  3  miles  below  Cumberland. 

Figs.  14,  15.     PAL^ONEILO  ROWEI  Prosser  n.  sp 244 

14.  Internal  impression  of  left  valve,  showing  muscular  markings  and. 

hinge  crenulations. 

15.  Squeeze  of  same  specimen. 

Romney  formation,  Hamilton  member,  McCoys  Ferry. 

Fig.  16.     PAL^ONEILO  MARYLAXDICA  Prosser  n.  sp 245 

Right  valve.     Hancock-Harrisonville   Road,   about   2   miles  north  of 
Hancock.    Romney  formation,  Hamilton  member. 


no 


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MIDDLE  DEVONIAN,   PLATE  XXVII 


' 


13 


15 


MOLLUSCA — PELECYPODA 


PLATE  XXVIII 

PAGE 

Figs.  1,  2.     TANCKEDIOPSIS  CLARKEI  Prosser  n.  sp 245 

1.  External  impression  of  right  valve.     X  1}4. 

2.  Squeeze  of  same  specimen,  showing  external  appearance  of  right 

valve.    X  1&. 

Romney  formation,  Hamilton  member,  Western  Maryland. 

Figs.  3,  4.     LEDA  DIVEKSA  Hall 247 

3.  Right  valve.     X  2.    Romney  formation,  Hamilton  member,  McCoys 

Ferry. 

4.  Left  valve.    X  2.    Hamilton  formation,  New  York. 

Figs.  5-7.     LEDA  ROSTELLATA  (Conrad) 247 

5.  Right  valve  of  young  specimen.     X  3.     Romney  formation,  Hamil- 

ton member,  National  Road  west  of  Tonoloway  Ridge. 

6.  7.  Right  and  left  valves.    X  2.    Hamilton  formation,  New  York. 

Figs.  8-12.     PARALLELODON  HAMILTONIJE    (Hall) 248 

8.  External  impression  showing  part  of  both  valves. 

9, 10.  Right  and  left  valves,  margins  partly  broken  away. 

Romney  formation,  Hamilton  member,  Evitts  Creek. 

11.  Right  valve  showing  surface  markings.    Hamilton  formation,  New 

York. 

12.  Left  valve  of  an  unusually  large  individual  from  near  Cumberland. 

(After  Hall.) 

Fig.  13.     LIOPTERIA  CF.  CONRADI  Hall 252 

Partly  exfoliated  left  valve.     Romney  formation,  Hamilton  member, 
Iron  bridge  over  Town  Creek,  northeast  of  Oldtown. 

Fig.  14.     LIOPTERIA  CONRADI  Hall 252 

A  large  left  valve.    Hamilton  formation,  New  York. 


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MARYLAND  GEOLOGICAL   SURVEY 


MIDDLE   DEVONIAN,   PLATE  XXVIII 


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10 


13 


14 


MOLLUSCA  —  PELECYPODA 


PLATE  XXIX 

PAGE 

Figs.  1-4.     PTERINEA  FLABELLUM  (Conrad) 250 

1.  Left  valve,  showing  alternation  in  size  of  radiating  ribs.     Evitts 

Creek. 

2.  Internal   impression    of   left   valve,    showing   muscular   scar   and 

striated  ligamental  area.    Iron  Bridge  over  Town  Creek,  north- 
east of  Oldtown. 

3.  Internal  impression  of  left  valve,  broken  toward  the  front;   but 

showing  well  the  striated  ligamental  area.    Flintstone  Creek  in 
Gilpin. 

4.  Right  valve,  partly  exfoliated.    Evitts  Creek. 

Romney  formation,  Hamilton  member. 

Fig.  5.     PTERIXEA  sp.  undet 251 

Left  valve  showing  surface  ornamentation.    Romney  formation,  Onon- 
daga  member,  Little  Moccasin  Gap,  Va.     (After  Kindle.) 

Fig.  6.     LIOPTERIA  L^VIS  Hall 253 

Left  valve.     X  2.    Romney  formation,  Onondaga  member,  three  miles 
east  of  Cumberland.     (After  Kindle.) 

Figs.  7-10.     LEPTODESMA  ROGERSI  Hall 254 

7,  8.  External   impression    X  2   and   squeeze   of   left  valve.     Romney 

formation,  Hamilton  member,  Evitts  Creek. 
9.  Block  showing  two  right  valves.     X  2. 
10.  Left  valve. 

Hamilton  formation,  New  York. 

Figs.  11-13.     MYTILARCA  (PLETHOMYTILUS)  OVIFORJIIS  (Conrad) 255 

11.  An  imperfect  right  valve.    21st  Bridge. 

12.  Another  imperfect  right  valve.    Evitts  Creek. 

Romney  formation,  Hamilton  member. 

13.  Left  valve  of  a  young  shell  of  elongate  form.    Hamilton  formation, 

New  York. 


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PLATE  XXX 

PAGE 

Figs.  1,  2.     CONOCARDIUM  NORMALE  Hall 257 

Right  side  and  cardinal  view  of  large  partial  cast  of  exterior.  Romney 
formation,  Hamilton  member,  Cumberland.  (After  Hall.) 

Figs.  3,  4.     COXOCARDIUM  CUMBERLANDI.E  Swartz  n.  sp 257 

Right  side  and  ventral  view  of  type.  Romney  formation,  Hamilton 
member,  Williams  Road,  3%  miles  east  of  Cumberland. 

Figs.  5-8.     ACTINOPTER.IA  DECUSSATA  Hall 258 

5.  Partly  exfoliated  left  valve. 

6.  Left  valve. 

7.  External  impression  of  a  portion  of  a  left  valve,  showing  the  char- 

acter of  the  surface  markings. 

Romney  formation,  Hamilton  member,  road  east  of  Pine  Hill, 
about  4  miles  north  of  Oldtown. 

8.  A  large  right  valve.    Hamilton  formation,  New  York. 

Figs.  9,  10.     ACTINOPTERIA  BOYDI  VAR.  GiBBosA  Prosser  n.  var 259 

9.  Right  valve. 
10.  Left  valve  of  same  specimen. 

Romney  formation,  Hamilton  member,  Town  Creek,  4  miles 
northeast  of  Oldtown. 

Fig.  11.     ACTINOPTERIA  sp 260 

Left  valve,  surface  markings  mostly  obliterated  over  the  umbonal 
region.  Romney  formation,  Hamilton  member,  Iron  Bridge  over 
Town  Creek,  northeast  of  Oldtown. 


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16 


PLATE  XXXI 

PAGE 

Figs.  1-5.     MODIELLA  PYGM.EA   (Conrad) 261 

1.  Right  valve  upon  which  the  fine  radiating  striae  are  faintly  shown. 

X  2.    Evitts  Creek. 

2.  External  impression  of  right  valve.    X  2.    Evitts  Creek. 

3.  Internal  impression  of  left  valve,  showing  anterior  muscular  scar 

and  oblique  sinus.    X  1%.    Hill  3  miles  south  of  Cumberland  in 
West  Virginia. 

4.  Cardinal  view  of  same  specimen.     X  I1/!- 

Romney  formation,  Hamilton  member. 

5.  Left  valve  showing  fine  radiating  stria?.    X  2.    Hamilton  formation, 

New  York. 

Fig.  6.     NYASSA  ABGUTA  Hall  (?) 262 

Internal  impression  of  a  broken  left  valve,  showing  impressions  of 
posterior  lateral  teeth.  Romney  formation,  Hamilton  member, 
McCoys  Ferry. 

Figs.  7-9.     NYASSA  ARGUTA  Hall 262 

7,  8.  Right  and  left  valves. 

9.  A  squeeze  showing  the  appearance  of  the  interior  of  the  right  valve. 

Hamilton  formation,  New  York. 

Figs.  10,  11.     AVICULOPECTEN  PRINCEPS    (Conrad) 263 

10.  A  specimen  preserving  both  valves. 

11.  A  large  left  valve,  much  extended  posteriorly. 

Hamilton  formation,  New  York. 

Fig.  12.     AVICULOPECTEN  sp 266 

An  incomplete  right  valve.  Romney  formation,  Hamilton  member, 
near  Hancock. 


MARYLAND  GEOLOGICAL  SURVEY 


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10 


11 


MOLLUSCA PELECYPODA 


PLATE  XXXII 

PAGE 

Figs.  1,  2.     AVICULOPECTEN  PRIXCEPS  (Conrad) 263 

1.  External  impression  of  a  broken  left  valve. 

2.  Left  valve  with  broken  margins. 

Romney   formation,    Hamilton   member,    Williams   Road,    % 
mile  east  of  Queen  City  Hotel,  Cumberland. 

Figs.  3,  4.     AVICULOPECTEX   EQUILATERA    (Hall) 265 

Two  left  valves  showing  variation  in  erectness  of  the  shell.  X  2. 
Romney  formation,  Onondaga  member,  Blair  County,  Penna., 
and  Ridgeville,  W.  Va.  (After  Kindle.) 

Figs.  5-9.     MODIOMORPHA  CONCENTRICA   (Conrad) i 266 

5,  6.  Right  and  left  valves.    Evitts  Creek. 

7,  8.  Internal  impression  of  right  and  left  valves.     Williams  Road, 

east  of  Evitts  Creek. 

9.  Internal  impression  of  right  valve  elongated  by  pressure,  showing 
anterior  muscular  scar.    Western  Maryland. 
Romney  formation,  Hamilton  member. 


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PLATE  XXXIII 

PAGE 

Figs.  1-6.     MODIOMORPHA  SUBALATA   (Conrad) 268 

I,  2.  Right  and  left  valves. 

3.  Right  valve. 

4.  Left  valve  of  small  specimen.    X  2. 

5.  Probably  right  valve  of  young  specimen.    X  2. 

6.  An  imperfect  right  valve. 

Romney  formation,  Hamilton  member,  Evitts  Creek. 

Fig.  7.     MODIOMORPHA  MYTILOIDES  (Conrad)   (?) 269 

Left  valve  from  which  umbonal  region  is  broken. 

Romney  formation,  Hamilton  member,  Evitts  Creek. 

Figs.  8-10.     MODIOMORPHA  MYTILOIDES    (Conrad) 269 

8,  9.  Right  and  left  valves. 
10.  Young  specimen  showing  both  valves. 
Hamilton  formation,  New  York. 

Figs.  11-13.     GONIOPHORA   HAMILTON  ENSIS    Hall 271 

II.  Partly  exfoliated  right  valve,  showing  sharp  umbonal  ridge.    Rom- 

ney formation,  Hamilton  member,  Hancock-Harrisonville  Road, 
about  2  miles  north  of  Hancock. 
12, 13.  Right  and  left  valves.    Hamilton  formation,  New  York. 

Figs.  14-16.     PHOLADELXA  RADIATA   (Conrad) 272 

14, 15.  Right  and  left  valves.     Hancock-Harrisonville  Road,  about  2 

miles  north  of  Hancock. 
16.  Cardinal  view  of  a  specimen.    Cumberland. 

Romney  formation,  Hamilton  member  (fig.  16,  after  Hall). 


116 


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13 


14 


10 


15 


MOLLUSCA — PELECYPODA 


PLATE  XXXIV 

PAGK 

Figs.  1-4.     CYPRICARDELLA  BELLISTRIATA  (Conrad) 273 

1.  Right  valve.    Evitts  Creek. 

2.  Interior  of  left  valve  (?)  with  broken  anterior  end.    Evitts  Creek. 

3.  Left  valve.    Evitts  Creek. 

4.  Cardinal  view  of  small  specimen  preserving  both  valves.     Cum- 

berland. 
Romney  formation,  Hamilton  member  (fig.  4,  after  Hall). 

Fig.  5.     CYPRICARDELLA  TENUISTRIATA  (Hall) 275 

Left  valve.  Romney  formation,  Hamilton  member,  Williams  Road, 
%  mile  east  of  Queen  City  Hotel,  Cumberland. 

Figs.  6-10.     CYPRICARDINIA  IXDENTA  (Conrad) 276 

6.  Right  valve.    X  2.    Evitts  Creek. 

7.  External  (?)  impression  of  right  valve.     X  2.    21st  Bridge. 

8.  A  squeeze  from  the  same  specimen.     X  2. 

Romney  formation,  Hamilton  member. 

9.  Right  valve  showing  surface  markings. 
10.  Left  valve. 

Hamilton  formation,  New  York. 

Figs.  11-14.     PARACYCLAS  LIRATA  Conrad 277 

11.  Right  valve  of  small  specimen.    Great  Cacapon. 

12.  Left  valve  elongated  by  pressure.    McCoys  Ferry. 

13, 14.  Right  and  left  valves  somewhat  distorted.    Western  Maryland. 
Romney  formation,  Hamilton  member. 

Fig.  15.     PARACYCLAS  LIRATA  Conrad  var.  (?) 278 

Left  valve  somewhat  broken  along  the  hinge  line.  Romney  formation, 
Hamilton  member,  McCoys  Ferry. 

Figs.  16,  17.     PARACYCLAS  TENTHS  Hall 278 

Interior  of  right  valves.     X  IV2.    Romney  formation,  Hamilton  mem- 
ber, Evitts  Creek. 

Fig.  18.     PAL^OSOLEX  MINUTTJS  Prosser  n.  sp 279 

Both  valves,  ventral  margin  of  left  broken^  X  1%.  Romney  forma- 
tion, Hamilton  member,  Williams  Road,  x/i  mile  east  of  Queen 
City  Hotel,  Cumberland. 


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MIDDLE  DEVONIAN,  PLATE  XXXIV 


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11 


- 


12 


13 


15 


16 


17 


MOLLUSCA — PELECYPODA 


PLATE  XXXV 

PAGE 

Figs.  1-5.     PLEUROTOMARIA  (BEMBEXIA)  SULCOMARGWATA  Conrad 280 

1.  Ventral  view  of  specimen.    Warrior  Mountain,  east  of  Rush. 

2.  View  of  spire  and  upper  part  of  body  whorl.    Right  bank  of  Potomac, 

about  3  miles  below  Cumberland. 

3.  4.  External  and  internal  impressions.    Western  Maryland. 

Romney  formation,  Hamilton  member. 

5.  Dorsal   view  of  specimen,  showing  surface  character.     Hamilton 

formation,  New  York. 

Figs.  6-8.     PLEUROTOMARIA  (GYROMA)  CAPILLARIA  Conrad 282 

6.  Dorsal  view,  showing  surface  markings.    X  1^4. 

7.  Body  whorl  showing  the  surface  markings  but  shell  is  exfoliated 

from  the  spire.    X  1*4. 
Romney  formation,  Hamilton  member,  Evitts  Creek. 

8.  Enlarged  specimen,  showing  surface  characters.     X  2.     Hamilton 

'    formation,  New  York. 

Figs.  9,  10.     PLEUROTOMARIA  (TREPOSPIRA)  ROT  ALIA  Hall  (?) 283 

9.  Part  of  body  whorl,  showing  surface  markings.     X  1%.    National 
Road,  west  of  Tonoloway  Ridge. 

10.  Internal  impression  of  body  whorl.     X  11A.    McCoys  Ferry. 

Romney  formation,  Hamilton  member. 

Figs.  11,  12.     PLEUROTOMARIA  (EURYZONE)  ITYS  Hall  (?) 284 

11.  Dorsal  view  of  internal  impression.    Robinson  farm,  2  miles  south 

of  Patterson  Depot,  W.  Va. 

12.  Ventral  view  of  internal  impression.    Western  Maryland. 

Romney  formation,  Hamilton  member. 

Fig.  13.     PLEUROTOMARIA  (EURYZONE)  ITYS  Hall 284 

View  of  an  internal  impression  retaining  traces  of  the  surface  charac- 
ters toward  the  aperture.  Hamilton  formation,  New  York. 

Fig.  14.     BELLEROPHON  ( PATELLOSTIUM )  PATULUS  Hall  (?) 287 

Dorsal  view  of  smooth  internal  impression  from  which  the  margins  are 
broken.  Romney  formation,  Hamilton  member,  Western  Mary- 
land. 

Fig.  15.     BELLEROPHON  (PATELLOSTIUM)  PATULUS  Hall 287 

Dorsal  view  of  specimen.    Hamilton  formation,  New  York. 


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PLATE  XXXVI 

PAGE 

Figs.  1-3.     BELLEROPHON  (BUCANOPSIS)  LEDA  Hall 285 

1.  Dorsal  view,  showing  surface  markings.     X  la/4.     Romney  forma- 

tion, Hamilton  member,  Evitts  Creek. 

2.  Dorsal  view  of  specimen  with  finely  preserved  surface.    X  2. 

3.  View  of  one  side  of  dorsal  surface,  showing  surface  markings.    X  3. 

Hamilton  formation,  New  York. 

Figs.  4-7.     CYRTOLITES  (CYRTONELLA)  MITELLA  Hall 288 

4.  Dorsal  view  of  specimen  which  is  crushed  on  right  side.    X  1^4. 

5.  Dorsal  view  of  smaller  specimen  which  is  distorted  toward  the 

front.    X  l1^. 

Romney  formation,  Hamilton  member,  road  east  of  Pine  Hill, 
about  4  miles  north  of  Oldtown. 

6.  Dorsal  view  of  partly  exfoliated  specimen. 

7.  Side  view  of  the  type,  an  internal  impression. 

Hamilton  formation,  New  York. 

Figs.  8,  9.     CYCLONEMA  LIRATUM  VAR.  GRABAUI  Prosser  n.  var 290 

8.  Squeeze  from  an  external  impression,  showing  part  of  the  body 

whorl,  the  spire  and  surface  markings.     X  1%. 

9.  Probably  the  internal  impression  of  the  body  whorl  of  the  same 

specimen.    X  1^4. 

Romney  formation,  Hamilton  member,  Williams  Road,  about 
3^  miles  southeast  of  Cumberland. 

Fig.  10.     CYCLONEMA  ( ?)  MARYLANDENSE  Prosser  n.  sp 292 

Side  view,  showing  the  surface  markings.  Romney  formation,  Hamil- 
ton member,  right  bank  of  Potomac  River,  4  miles  below  Cum- 
berland. 

Fig.  11.     NATICOPSIS  sp.  undet 293 

Lateral  view.  X  4.  Romney  formation,  Onondaga  member,  Ridge- 
ville,  W.  Va. 

Figs.  12-15.     MACROCHILUS  HAMILTONI^;  Hall 293 

12, 13.  Dorsal   and   ventral   views  of  internal   impression.     Romney 

formation,  Hamilton  member,  Western  Maryland. 
14, 15.  Views  of  the  opposite  sides  of  the  type.    Hamilton  formation, 

New  York. 

Figs.  16-19.     LOXONEMA  HAMILTONI.E  Hall 294 

16.  Dorsal  view,  showing  strong  longitudinal  striae.    X  1%.    4^  miles 

northeast  of  Oldtown. 

17.  Body  whorl,  showing  longitudinal  striae.     X  2.     Evitts  Creek. 

Romney  formation,  Hamilton  member. 

18, 19.  Dorsal  and  ventral  views  of  specimen  of  usual  size.  Hamilton 
formation,  New  York. 


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13 


14 


11 


17 


15 


PLATE  XXXVII 

PAGE 

Pigs.  1-3.     PLATYCERAS  ERECTUM  Hall   (?) 296 

1.  Lateral  view  of  partly  exfoliated  specimen.     X  1*4. 

2,  3.  Two  views  of  exfoliated  specimen,  wrinkled  by  crushing  toward 

the  margin.     X  1*4. 

Romney  formation,  Hamilton  member,  Hancock-Harrisonville 
Road,  about  2  miles  north  of  Hancock. 

Figs.  4,  5.     PLATYCERAS  ERECTUM  Hall 296 

Two  views  of  specimen  from  Hamilton  formation  of  New  York. 

Fig.  6.     PLATYCERAS  CF.  SYMMETRTCUM  Hall 297 

Dorsal  view  of  partly  exfoliated  specimen.  Romney  formation,  Hamil- 
ton member,  Evitts  Creek. 

Figs.  7-12.     DIAPHOROSTOMA  LINEATUM   (Conrad) 298 

7.  Lateral  view. 

8.  Enlarged  portion  of  same  to  show  surface  markings.     X  7. 

Romney  formation,  Hamilton  member,  Ernstville. 

9.  The  aperture  and  spire  of  a  symmetrical  specimen. 

10.  Lateral  view  of  the  same. 

11.  Side  view  of  a  specimen  preserving  the  surface  in  great  perfection. 

12.  Enlargement  of  the  surface  of  the  preceding. 

Hamilton  formation,  New  York. 

Figs.  13-15.     PLATYSTOMA  CF.  EUOMPHALOIDES  Conrad 299 

Upper,  side  and  lower  views.    Hamilton  formation,  New  York. 

Fig.  16.     (?)  GASTROPOD. 

Squeeze  from  external  impression  (?).  X  10.  Romney  formation, 
Hamilton  member,  road  east  of  Pine  Hill,  about  4  miles  north 
of  Oldtown. 

Figs.  17-20.     STYLIOLIXA  FISSURELLA  ( Hall) 300 

17.  Lateral  view  of  small  specimen.    X  6. 

18.  Similar  view  of  larger  specimen.     X  6. 

Romney  formation,  Hamilton  member,  Iron  Bridge  over  Town 
Creek,  northeast  of  Oldtown. 

19.  Specimen  strongly  striated  longitudinally.     X  6. 

20.  Specimen  showing  transverse  and  longitudinal  striae.     X  6. 

Marcellus  formation,  New  York. 

Fig.  21.     TENTACULITES   ATTEXUATUS   Hall 301 

Specimen  showing  internal  impression  for  larger  end  and  external 
impression  for  the  remainder.  X  5.  Romney  formation,  Hamil- 
ton member,  National  Road,  west  of  Tonoloway  Ridge. 

Figs.  22-25.     TENTACULITES  BELLULUS  Hall 302 

22.  External  impression.     X  3. 

23.  Same  enlarged  to  show  annulations  and  fine  transverse  striae.    X  8. 

Romney  formation,  Hamilton  member,  Iron  Bridge  over  Town 
Creek,  northeast  of  Oldtown. 

24.  A  specimen  showing  the  general  features  of  the  species. 

25.  Enlargement  of  the   same   showing  annulations   and   encircling 

striae. 

Hamilton  formation,  New  York. 


MARYLAND  GEOLOGICAL  SURVEY 


MIDDLE  DEVONIAN,   PLATE  XXXVII 


21 


19  20 


24 


23 


25 


MOLLUSCA — GASTROPODA 


PLATE  XXXVIII 

PAGE 

Figs.  1-3.     TENTACULITES  BELLULUS  VAR.  POTOMACENSIS  Prosser  n.  var 303 

1.  View  of  external  impression.    X  1%. 

2.  Squeeze  of  same,  showing  the  external  appearance  of  the  species. 

xi%. 

3.  Same  specimen  enlarged  to  show  annulations  and  transverse  striae. 

X  4. 
Romney  formation,  Hamilton  member,  McCoys  Ferry. 

Fig.  4.     CONTJLARIA  UNDULATA  Conrad 304 

Side  view  of  shell.    Hamilton  formation,  New  York. 

Figs.  5-8.     COLEOLUS  TENUICINCTUS  Hall 305 

5.  Two   specimens,   showing  concentric   striae;    median   longitudinal 

groove  due  to  fracture. 

6.  Part  of  right  hand  specimen  of  preceding  enlarged,  showing  appear- 

ance of  transverse  striae.     X  3. 

Romney  formation,  Hamilton  member,  Evitts  Creek. 

7.  An  imperfect  specimen. 

8.  A  fragment  enlarged. 

Hamilton  formation,  New  York. 

Fig.  9.     BACTRITES  ACICULUS   320 

Fragment  of  tube.    Romney  formation,  Onondaga  member,  Sassin,  Va. 
(After  Kindle.) 

Figs.  10,  11.     ORTHOCERAS  BEBRYX  Hall  (?) 307 

10.  Internal  impression  of  part  of  an  individual.    Oldtown  Road  near 

Cumberland. 

11.  Enlargement  showing  surface  markings.     X  4.    Great  Cacapon. 

Romney  formation,  Hamilton  member. 

Fig.  12.     ORTHOCERAS  BEBRYX  Hall 307 

A  much  compressed  and  weathered  fragment,  with  the  siphuncle  ex- 
posed.   Hamilton  formation,  New  York. 


121 


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\ 


MOLLUSCA — GASTROPODA  AND  CEPHALOPODA 


if, 


PLATE  XXXIX 

PAGE 

Figs.  1,  2.     ORTHOCERAS  SUBULATUM  Hall  (?) 308 

1.  Partly  exfoliated  living  chamber. 

2.  Septum  of  the  same,  showing  position  of  siphuncle. 

Romney  formation,  Hamilton  member,  right  bank  of  Potomac, 
3  miles  below  Cumberland. 

Figs.  3,  4.     ORTHOCERAS   SUBULATUM   Hall 308 

3.  The  apical  portion  of  a  specimen,  showing  the  regular  increase  in 

the  depth  of  the  air-chambers  from  the  apex  to  the  larger  ex- 
tremity. 

4.  A  septum,  showing  the  position  of  the  siphuncle. 

Hamilton  formation,  New  York. 

Figs.  5-8.     ORTHOCERAS  CONSTRICTUM  Vanuxem 309 

5.  Partly  exfoliated  living  chamber.     Romney  formation,  Hamilton 

member,  Oldtown  Road  near  Cumberland. 

6.  A  fragment  retaining  a  portion  of  the  living  chamber  and  twenty- 

one  air-chambers. 

7.  A  fragment  of  the  living  chamber,  with  two  of  the  attached  air- 

chambers. 

8.  A  septum,  showing  position  of  siphuncle. 

Hamilton  formation,  New  York. 

Fig.  9.     ORTHOCERAS  CF.  EXILE  Hall 310 

Specimen  showing  seven  air-chambers.    Romney  formation,  Hamilton 
member,  Evitts  Creek. 

Figs.  10,  11.     ORTHOCERAS  EXILE  Hall 310 

10.  Living  chamber  with  two  air-chambers. 

11.  Septum  of  same,  showing  the  circular,  transverse  section  of  the 

tube  and  the  excentric  position  of  the  siphuncle. 
Hamilton  formation,  New  York. 


122 


MARYLAND  GEOLOGICAL  SURVEY 


MIDDLE  DEVONIAN,  PLATE  XXXIX 


11 


MOLLUSCA — CEPHALOPODA 


PLATE  XL 

PAGE 

Figs.  1-4.     ORTHOCERAS  TELAMON  Hall   (?) 311 

1.  Internal  impression  of  living  chamber. 

2.  Septum  of  preceding,  showing  excentric  siphuncle. 

3.  A  specimen  showing  five  air-chambers. 

4.  Septum  of  preceding,  showing  excentric  siphuncle. 

Romney   formation,    Hamilton   member,   Robinsons    farm,   2 
miles  south  of  Patterson  Depot,  W.  Va. 

Figs.  5,  6.     OKTHOCERAS  TELAMON  Hall .". 311 

5.  Small  fragment  showing  depth  of  air-chambers  and  gradual  en- 

largement of  tube. 

6.  A  septum,  showing  very  excentric  position  of  siphuncle. 

Hamilton  formation,  New  York. 

Fig.  7.     ORTHOCERAS  EMACERATUM  Hall  (?) 313 

Internal  impression,  showing  six  air-chambers.  Romney  formation, 
Hamilton  member,  right  bank  of  Potomac,  3  miles  below  Cum- 
berland. 

Fig.  8.     ORTHOCERAS  CF.  ATJLAX  Hall 313 

Portion  of  living  chamber,  showing  surface  markings.  Romney  forma- 
tion, Hamilton  member,  road  east  of  Pine  Hill,  about  4  miles 
north  of  Oldtown. 

Fig.  9.     ORTHOCERAS  AULAX  Hall 313 

Fragment  of  living  chamber,  showing  the  prominent,  regular  trans- 
verse furrows  and  ridges  of  the  surface.  Hamilton  formation, 
New  York. 


123 


MARYLAND  GEOLOGICAL  SURVEY 


MIDDLE  DEVONIAN,  PLATE  XL 


-/ 


MOLLUSCA — CEPHALOPODA 


PLATE  XLI 

PAGE 

Figs.  1-5.     SPYBOCERAS  CROTALUM    (Hall) 314 

1.  Fragment,  showing  the  prominent   annulations  and   longitudinal 

striae. 

2.  Enlargement  of  same.    X  2. 

Romney  formation,  Hamilton  member,  Western  Maryland. 

3.  Internal  impression  of  portion  of  living  chamber,  showing  absence 

of  annulations  near  aperture  and  striate  surface. 

4.  A  small,  septate  fragment,  preserving  the  characteristic  fine,  longi- 

tudinal striae  over  the  exterior  of  the  tube. 

5.  A  small,  slightly  compressed  specimen,  showing  the  surface  mark- 

ings and  the  increase  in  prominence  of  the  annulations  toward 
the  larger  end. 

Hamilton  formation,  New  York. 

Figs.  6-8.     SPYROCERAS  XUXTIUM  Hall 316 

6.  Partly  exfoliated  fragment,  showing  the  surface  striae. 

7.  Shell  of  same  enlarged,  showing  surface  striae.    X  6. 

Romney  formation,  Hamilton  member,  right  bank  of  Potomac, 
3  miles  below  Cumberland. 

8.  A  compressed  specimen  showing  annulations  and  longitudinal  striae. 

Hamilton  formation,  New  York. 

Figs.  9-11.     SPYROCERAS  CLARKEI  Prosser  n.  sp 317 

9.  10.  Two  views  of  fragment,  showing  five   annulations  and  surface 

markings. 

11.  Same  enlarged,   showing  the  longitudinal  and  concentric   stria?. 
X3. 
Romney  formation.  Hamilton  member,  Ernstville. 


124 


MARYLAND  GEOLOGICAL  SURVEY 


MIDDLE  DEVONIAN,   PLATE  XLI 


11 


MOLLUSCA — CEPHALOPODA 


PLATE  XLII 

PAGE 

Figs.  1,  2.     CF.  GOMPHOCERAS  PINGUE  Hall 318 

1.  Part  of  living  chamber. 

2.  Septum  of  preceding,  showing  position  of  siphuncle. 

Romney  formation,  Hamilton  member,  Western  Maryland. 

Fig.  3.     GOMPHOCERAS  PINGUE  Hall 318 

Fragment  showing  ventricose  form  and  curvature  of  living  chamber 
toward  aperture.    Hamilton  formation,  New  York. 

Fig.  4.     BACTRITES  ACICULATUS    (Hall) 319 

Part  of  an  individual.    X  1%.    Romney  formation,  Hamilton  member, 
21st  Bridge. 

Fig.  5.     BACTRITES  ACICULUM  Hall 320 

Shell  slightly  crushed.    Genesee  formation,  New  York. 

Fig.  6.     AGONIATITES  EXPANSUS    (Vanuxem) 321 

Outline  figure  showing  character  of  surface  stria?.    Romney  formation, 
Onondaga  member,  Cumberland.     (After  Kindle.) 

Figs.  7,  8.     PARODICERAS  DISCOIDEUM  (Conrad) 323 

Lateral  and  ventral  views.    Marcellus  formation,  New  York. 

Fig.  9.     CYPHASIS  CF.  STEPHANOPHORA  Hall 326 

Fragmentary  glabella.     X  5.     Romney  formation,  Onondaga  member, 
Berkeley  Springs,  W.  Va.     (After  Kindle.) 


125 


MARYLAND  GEOLOGICAL  SURVEY 


MIDDLE   DEVONIAN,   PLATE  XLH 


'II 


xs 


MOLLUSCA — CEPHALOPODA  AND  ARTHROPODA — TRILOBITA 


PLATE  XLIII 

PAGE 

Figs.  1-7.     HOMALONOTUS  DEKAYI   ( Green) 328 

1.  A  young,  distinctly  trilobate  and  nearly  entire  individual. 

2.  An  enrolled  and  uncompressed  individual. 

3.  The  hypostoma. 

4.  An  enlargement  of  the  under  surface.    X  5. 

Hamilton  formation,  New  York. 

5.  Dorsal  view  of  a  pygidium. 

6.  A  smaller  and  somewhat  crushed  pygidium,  showing  the  reflexed 

apex. 

7.  An  enlargement  of  a  portion  of  the  surface  of  same.     X  10. 

Romney  formation,  Hamilton  member,  road  east  of  Pine  Hill, 
about  4  miles  north  of  Oldtown. 

Figs.  8-12.     PHACOPS  RANA  (Green) 329 

8.  Dorsal  view  of  cephalon.    21st  Bridge. 

9.  The  eye  of  same.    X  3. 

10.  Pygidium.     X  2.    Evitts  Creek. 

Romney  formation,  Hamilton  member. 

11.  A  small  individual. 

12.  The  eye  of  a  slightly  weathered  specimen  enlarged. 

Hamilton  formation,  New  York. 

Figs.  13-15.     PHACOPS  CBISTATA  Hall 331 

13.  Cephalon  and  part  of  the  thorax  of  an  enrolled  specimen,  showing 

axial  and  genal  spines.    Alinda,  Penna. 

14.  Lateral  view  of  an  enrolled  specimen  with  a  partly  crushed  gla- 

bella,  showing  genal  spine  base.    Alinda,  Penna. 

15.  Fragmentary  thorax  and  pygidium,  showing  axial  spines.     Ridge- 

ville,  W.  Va. 
Romney  formation,  Onondaga  member.     (After  Kindle.) 

Figs.  16,  17.     PHACOPS  CRISTATA  VAR.  PIPA  Hall 332 

16.  Fragmentary  enrolled  thorax.     Alinda,  Penna. 

17.  Pygidium,   showing   duplicate   character   of   pleural   anntilations. 

Near  New  Bloomfield,  Penna. 

Romney  formation,  Onondaga  member.     (After  Kindle.) 


126 


MARYLAND  GEOLOGICAL  SURVEY 


MIDDLE   DEVONIAN,   PLATE   XLIII 


12 


17 


'ARTHROPOD  A — TRILOBITA 


PAGE 

Figs.  1-4.     DALMANITES  (CRYPH^US)  BOOTHI  (Green) 333 

1.  Partly  exfoliated  pygidium  with  marginal  spines.     X  1%. 

2.  Another  partly  exfoliated  and  smaller  pygidium.     X  2. 

3.  A  pygidium  and  part  of  one  side  of  a  thorax.    X  1%. 

Romney  formation,  Hamilton  member,  Evitts  Creek. 

4.  Internal  surface  of  a  pygidium,  in  which  the  spines  are  broad  and 

flat.    Hamilton  formation,  New  York. 

Fig.  5.     DALMANITES  MARYLANDICUS  Prosser  n.  sp 334 

Partly  exfoliated  pygidium,  showing  the  pustulose  surface  and  two 
spines  at  the  apex.  Romney  formation,  Hamilton  member, 
Ernstville. 

Fig.  6.     LEPEKDITIA  ?  SUBROTUNDA ; 335 

Right  valve.  X  20.  Romney  formation,  Onondaga  member,  Little 
Moccasin  Gap,  Va.  (After  Kindle.) 

Figs.  7,  8.     BOLLIA  UNGULA  Jones 336 

7.  Cast  of  a  left  valve.     X  20.    Rees  Tannery,  Mineral  County,  W.  Va. 

8.  Dorsal   view  of   a   slightly   distorted    specimen.      X  20.      Berkeley 

Springs,  Ridgeville,  W.  Va. 

Romney  formation,  Onondaga  member.     (After  Kindle.) 

Fig.  9.     BOLLIA  OBESA  Ulrich 337 

Cast  of  left  valve.  X  20.  New  Bloomfield,  Penna.  Romney  formation, 
Onondaga  member.  (After  Kindle.) 


MARYLAND  GEOLOGICAL  SURVEY 


MIDDLE  DEVONIAN,   PLATE  XLIV 


XZO 


ARTHROPODA — TRILOBITA  AND  OSTRACODA 


DEVONIAN 

UPPER 


NOTE 

The  following  plates   (Plates  XLV  to  LXXIII)   illustrate  the  Systematic 
Paleontology  of  the  Upper  Devonian  of  Maryland. 


17 


PLATE  XLV 

PAGE 

Pigs.  1,  2.     ZAPHRENTIS  MARYLANDICUS  n.  sp 539 

1.  Cast  of  calyx  of  type  specimen  as  seen  from  below. 

2.  Side  view  of  preceding  showing  its  relation  to  outline  of  corallite. 

Jennings  formation,  Chemung  member,  National  Road,  Polish 
Mountain,  2714.1 

Figs.  3-6.     ZAPHRENTIS  CHEMUNGENSIS  n.  sp 540 

3.  Side  view  of  cast  of  interior  of  calyx,  showing  its  relation  to  shape 

of  corallum. 

4.  Lower  surface  of  preceding. 

5.  View  of  type  specimen,  similar  to  fig.  3. 

6.  Lower  surface  of  same  individual. 

Jennings  formation,  Chemung  member,  Polish  Mountain,  2714. 

Figs.  7,  8.     HELIOPHYLLUM  SCRUTARIUM  n.  sp 540 

7.  Branching  corallum  showing  calyxes. 

8.  Specimen  similar  to  preceding. 

Jennings  formation,  Chemung  member  ?,  Sideling  Hill  Creek, 
Washington  County. 

Fig.  9.     FAVOSITES  sp 541 

A  small  corallum  showing  size  of  the  cells.    Jennings  formation,  Che- 
mung member  ?,  Sideling  Hill  Creek,  Washington  County. 

Figs.  10,  11.     AULOPORA  REPENS  Knorr  and  Walch 542 

10.  Corallum  attached  to  shell  of  Rhipidomella  vanuxemi. 

11.  Corallum  similarly  attached,  showing  some  difference  in  propor- 

tion of  corallites. 

Jennings  formation,  base  of  Parkhead  member,  hill-top  south 
of  Potomac  River,  2V2  miles  southeast  of  Cumberland. 


1  The  figures  following  localities  indicate  the  altitude  in  feet  above  the  base 
of  the  Jennings  formation  at  which  the  specimens  were  found. 


128 


MARYLAND  GEOLOGICAL  SURVEY 


UPPER  DEVONIAN,  PLATE  XLV 


11 


CCELENTERATA — ANTHOZOA 


PLATE  XLVI 

PAGE 

Figs.  1,  2.     CLADOCHONUS  HUMIIJS  n.  sp 542 

1.  Corallum,  natural  size.    Hancock-Harrisonville  Road,  2  miles  north 

of  Hancock,  725. 

2.  Cast  of  interior  of  corallite,  showing  imprints  of  spinules.     X  5. 

National  Road,  east  of  Hancock,  690. 

Jennings  formation,  Woodmont  member,  Ithaca  fauna. 

Figs.  3,  4.     PALEASTER  CLARKI  n.  sp 543 

3.  Ambulacral  surface,  showing  the  character  of  the  thecal  plates, 

and  some  of  the  adambulacral  plates.    The  mouth  parts  are  not 
clearly  retained.     X  1%. 

4.  Abactinal  surface,  showing  the  character  of  the  three  rows  of  plates 

on  the  arms,  the  fine  intercalary  plates  of  the  median  row  and 
the  large  and  mammillated  body  plates.     X  1%. 
Jennings  formation,  Chemung  member,  near  Oakland. 

Fig.  5.     SPIRORBIS  GYRUS  n.  sp 544 

An  attached  tube,  showing  the  tubercled  surface.  X  5.  Jennings 
formation,  Chemung  member  ?,  Sideling  Hill  Creek,  Allegany 
County. 

Fig.  6.     PTERIDICHNITES  BISERIATUS  n.  sp 545 

Track  made  by  animal.  Jennings  formation,  Woodmont  member, 
Naples  fauna,  Woodmont. 


129 


MARYLAND  GEOLOGICAL  SURVEY 


UPPER   DEVONIAN,  PLATE  XLVI 


COELENTERATA — VERMES — ECHINODERMATA 


PLATE  XLVII 

PAGE 
Figs.  1-5.     LINGULA  OHERNI  n.  sp 546 

1.  Small  shells  probably  young  of  this  species. 

2.  Single  valve  from  preceding  group.    X  6. 

3-4.  Exteriors  of  valves  showing  slight  differences  of  form. 

5.  Interior  of  valve. 

Jennings  formation,  Parkhead  member,  Williams  Road,  S1/^ 
miles  east  of  Cumberland,  1393. 

Figs.  6,  7.     LINGULA  LIGEA  Hall 547 

6.  Exterior  of  valve.    X  3. 

7.  Exterior  of  valve  which  differs  slightly  in  form.    X  3. 

Jennings  formation,  Woodmont  member,  National  Road,  east 
of  Hancock,  1564  to  1599. 

Fig.  8.     LINGULA  SPATULATA  Vanuxem 548 

Exterior  of  valve.  X  6.  Jennings  formation,  Woodmont  member, 
Ithaca  fauna,  National  Road,  east  of  Hancock,  1149  to  1274. 

Figs.  9,  10.     OEBICULOIDEA  CF.  MEDIA  (Hall) 549 

9.  Dorsal  valve.    Chemung  formation,  New  York. 

10.  Dorsal  valve  somewhat  distorted.     Jennings  formation,  Parkhead 
member,  Williams  Road,  3%  miles  east  of  Cumberland,  1393. 

Figs.  11-13.     CBAINELLA  HAMILTOXI^E  Hall 549 

11.  Cast  of  interior  of  dorsal  valve.    The  vascular  markings  are  visible 
upon  cast,  but  are  not  shown  in  figure.     Jennings  formation, 
Parkhead  member,  Williams  Road,  Polish  Mountain,  1660. 
12, 13.  Exterior  and  cast  of  interior  of  dorsal  valve.    Jennings  forma- 
tion, Chemung  member,  Ellerslie,  Penna.,  1474. 

Fig.  14.     STBOPHEODONTA  DEMISSA   (Conrad) 551 

Dorsal  view  of  shell.  Jennings  formation,  Woodmont  member,  Ithaca 
fauna,  Hancock-Harrisonville  Road,  2  miles  north  of  Hancock, 
882. 

Figs.  15-18.     STROPHEODONTA  MAYNARDI  n.  sp 551 

15.  Ventral  valve  of  type. 

16.  Dorsal  valve. 

17.  Enlargement  of  cast  of  portion  of  interior  of  dorsal  valve.    X  2. 

18.  Enlargement  of  a  portion  of  a  cast  of  the  interior  of  the  ventral 

valve  showing  hinge  and  muscular  scars.    X  2. 

Jennings  formation,  Chemung  member,  Town  Creek,  2391. 


130 


MARYLAND  GEOLOGICAL  SURVEY 


UPPER   DEVONIAN,   PLATE  XLVII 


3 


10 


11 


12 


13 


18 


MOLLUSCOTDEA — BRACHIOPODA 


PLATE  XLVIII 

PAGE 

Figs.  1-4.     LEPTOSTROPHIA  PEBPLAXA  VAR.  NERVOSA  (Hall) 552 

1.  The  interior  of  a  ventral  valve. 

2.  Ventral  valve  showing  the  character  of  the  surface. 

3.  Internal  cast  of  an  average  ventral  valve  showing  muscular  scars 

and  denticulate  hinge. 

4.  Interior  of  the  dorsal  valve  showing  the  double  cardinal  process, 

muscular  fulcra,  and  pustulose  patches  about  the  muscular  area. 
Jennings  formation,  Chemung  member,  from  localities  near 
Deer  Park  and  Oakland. 

Figs.  5,  6.     LEPTOSTROPHIA  PERPLANA  VAR.  ALTERNATA  n.  var 553 

5.  Cast  of  exterior  of  ventral  valve,  hinge-line  imperfect. 

6.  Enlargement  of  striae.    X  5. 

Jennings  formation,  Chemung  member,  Town  Creek,  2391. 

Fig.  7.     LEPTOSTROPHIA  INTERSTRIALIS    (Vanuxem) 554 

Ventral  valve.  Striae  of  shell  are  less  regular  than  shown  and  some- 
what nodose.  Jennings  formation,  Woodmont  member,  Ithaca 
fauna,  National  Road,  east  of  Millstone,  795. 

Figs.  8-17.     DOUVILLINA  CAYUTA  (Hall) 555 

8.  A  small  ventral  valve  of  average  proportions. 
9, 10.  Two  broader  ventral  valves. 

11.  External  cast  of  dorsal  valve. 

12.  Dorsal  valve. 

13.  Interior  of  ventral  valve  showing  the  clearly  defined  brachial  de- 

pressions in  front  of  the  muscle  scars. 

14.  A  characteristic  internal  cast  of  the  ventral  valve  showing  mus- 

cular scars  and  crenulate  hinge. 

15.  Internal  cast  of  a  larger  ventral  valve. 

16.  Internal  cast  of  ventral  valve. 

17.  Enlargement  of  the  cardinal  portion  of  the  dorsal  valve. 

Jennings  formation,  Chemung  member,  Deer  Park,  Oakland 
and  Altamont. 


131 


MARYLAND  GEOLOGICAL  SURVEY 


UPPER   DEVONIAN,   PLATE  XLVIII 


It      , 


15 





14 


MOLLUSCOIDEA — BRACHIOPODA 


PLATE  XLIX 

PAGE 

Figs.  1,  2.     DOUVILLINA  CAYUTA    (Hall) 555 

1.  Interior  of  dorsal  valve. 

2.  Enlargement  of  internal  cast  of  dorsal  valve.     X  2. 

Jennings  formation,  Chemung  member,  Oakland  and  Deer 
Park. 

Figs.  3-13.     DOUVILLINA  CAYUTA  VAR.  GBACILIORA  n.  var 556 

3.  Ventral  valve.    X  3. 

4.  Ventral  valve  represented  somewhat  too  concave  at  the  umbo. 

5.  Ventral  valve. 

6.  Dorsal  view  of  shell.    X  3. 

7.  8.  Internal  casts  of  ventral  valves. 

9.  Dorsal  view  of  a  larger  specimen.    X  2. 
10.  Ventral  valve  similar  to  fig.  1. 

11, 12.  Upper  and  profile  views  of  a  characteristic  ventral  valve.    X  2. 
13.  Profile  view  of  ventral  valve. 

Jennings  formation,  Chemung  member,  Deer  Park  and  Oak- 
land. 

Figs.  14-17.     DOUVILLIXA  ARCUATA  (Hall) 557 

14, 15.  Upper  and  profile  views  of  a  typical  ventral  valve.  X  2.  From 
Upper  Devonian  of  Lime  Creek,  Iowa.  (Introduced  for  com- 
parison with  following.) 

16, 17.  Upper  and  profile  views  of  a  ventral  valve  believed  to  be  of  this 
species. 

Jennings   formation,   Chemung   member,   National   Road,    6 
miles  west  of  Frostburg. 

Fig.  18.     STROPHOXEIXA  CF.  REVEKSA  (Hall) 557 

The  interior  of  a  dorsal  valve  showing  the  reversed  convexity,  cardinal 
process,  hinge  and  median  sinus.  Jennings  formation,  Che- 
mung member,  Trout  River,  near  Oakland. 

Figs.  19-22.     SCHUCHERTELLA  CHEMUNGENSis   (Conrad) 559 

19.  Interior  of  small  dorsal  valve.    Deer  Park. 

20.  Dorsal  valve.    Wills  Creek  Station. 

21.  22.  Upper  and  cardinal  views  of  a  ventral  valve.    Two  miles  east 

of  Oakland. 

Jennings  formation,  Chemung  member. 


132 


MARYLAND  GEOLOGICAL  SURVEY 


UPPER   DEVONIAN,   PLATE  XLIX 


.<"i!i!ij;:.'.;i-:M 


3?ar 


18 


MOLLUSCOIDEA — BRACHIOPODA 


PLATE  L 

PAGE 

Figs.  1-3.     SCHUCHERTELLA  CHEMUNGENSis   (Conrad) 559 

1.  Dorsal  valve.    Deer  Park. 

2.  Dorsal  valve  showing  impress  of  cardinal  process.     Top  of  Polish 

Mountain. 

3.  Internal  cast  of  a  very  broad  ventral  valve.    Near  Deer  Park. 

Jennings  formation,  Chemung  member. 

Fig.    4.       SCHUCHERTELLA   ELLIPTICA   n.    Sp 560 

Cast  of  interior  of  ventral  valve.  Jennings  formation,  Chemung  mem- 
ber, Town  Creek,  4631. 

Fig.    5.       SCHUCHERTELLA   (?)   PONDEROSA  n.  SP 560 

Cast  of  interior  of  a  distorted  ventral  valve  showing  muscular  scars. 
Jennings  formation,  Chemung  member,  National  Road,  east  of 
Millstone,  2444. 

Figs.  6-10.     CHONETES  LEPIDIFORMIS  n.  sp 561 

6.  Ventral  valve  retaining  long  cardinal  spines  and  showing  the  sur- 

face characters.     X  3.    National  Road,  Polish  Mountain. 

7.  Internal  cast  of  ventral  valve.     X  2.    Same  locality  as  preceding. 

8.  Very  large  ventral  valve.    X  2. 

9.  Internal  cast  of  ventral  valve.    X  3. 

10.  More  transverse  ventral  valve.     X  3.     Figs.  8,  9,  and  10  are  from 
National  Road,  east  of  Millstone. 

Jennings  formation,  Parkhead  member. 

Figs.  11-13.     CHONETES  SCITULUS  Hall 563 

11.  Ventral  valve.     X  2.     Near  base   of   Parkhead   member,   cut   of 

Baltimore  and  Ohio  Railroad,  Rocky  Run,  7  miles  southeast  of 
Cumberland. 

12.  Cast  of  interior  of  ventral  valve  showing  papillose  surface.     X  2. 

Same  locality. 

13.  Ventral  valve  having  finer  striae.    Williams  Road,  Polish  Mountain, 

1422. 
Jennings  formation,  Parkhead  member. 

Figs.  14-18.     CHONETES  OAKLANDENSIS  n.  sp 562 

14-16.  Three  ventral  valves.     X  2. 
17, 18.  Two  dorsal  valves.     X  2. 

Jennings   formation,   Chemung   member,    Green    Glade   Run, 
near  Deer  Park. 

Fig.  19.     CHONETES  ROWEI  n.  sp 563 

Ventral  valve  showing  irregular  bifurcating  spinulose  plications.  X  3. 
National  Road,  east  of  Millstone.  Jennings  formation,  Park- 
head  member. 

Figs.  20-22.     PRODUCTEIXA  LACHRYMOSA   (Conrad) 564 

20.  Ventral  valve  of  typical  form.    Sideling  Hill  Creek,  2%  miles  above 

mouth,  1700. 

21.  Ventral  valve  of  small  individual.    Williams  Road,  Polish  Moun- 

tain, 1660. 

22.  Ventral  valve  upon  which  spines  are  somewhat  closer  than  usual. 

Same  locality  as  preceding. 
Jennings  formation,  Parkhead  member. 

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18 


21 


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PAGE 

Figs.  1-3.     PRODUCTELLA  LACHRYMOSA   (Conrad) 564 

1.  Small  cast  of  ventral  valve. 

2.  Ventral  valve. 

3.  Sculpture  cast  of  ventral  valve. 

Jennings  formation,  Chemung  member,  top  of  Polish  Moun- 
tain. 

Figs.  4-9.     PRQDUCTELLA  LACHRYMOSA  VAR.  MARYLAXDICA  n.  var 565 

4.  A  large  ventral  valve  which  differs  somewhat  from  the  remaining 

specimens.    Williams  Road,  Polish  Mountain,  2042. 

5.  6.  Interiors  of  dorsal  valves. 

7-9.  Ventral  valves  showing  sparsely  spinulose  surface.    Polish  Moun- 
tain. 
Jennings  formation,  Chemung  member. 

Figs.  10-12.     PRODUCTELLA  LACHRYMOSA  (Conrad)  var 565 

10, 11.  Ventral  valves. 

12.  Portion  of  surface  of  valve  shown  in  fig.  10,  enlarged  X  5. 

Jennings  formation,  Chemung  member,  3%   miles  south  of 
Oakland. 

Figs.  13-15.     PRODUCTELLA  SPECIOSA  Hall 566 

13.  Ventral  valve.    Hancock-Harrisonville  Road,  2  miles  north  of  Han- 

cock, 1213. 

14.  Ventral  valve  showing  spinules.    Woodmont,  1067. 

15.  Dorsal  valve.    National  Road,  east  of  Millstone,  795. 

Jennings  formation,  Woodmont  member,  Ithaca  fauna. 

Figs.  16-19.     PRODUCTELLA  HYSTRICULA  (Hall) 567 

16, 17.  Dorsal  valves. 

18.  Ventral  valve. 

19.  Ventral  valve  showing  spinules. 

Chemung  formation,  New  York. 

Fig.  20.     PRODUCTELLA  NAVICELLIFORMIS  n.  sp 567 

Ventral  valve  of  type.    Jennings  formation,  Parkhead  member,  Town 
Creek,  2228. 

Figs.  21-23.     PRODUCTUS  (MARGINIFERA  ?)  HALLANUS  Walcott 568 

21,  22.  Ventral  and  dorsal  views  of  a  typical  specimen  from  the  Upper 

Devonian  of  Lime  Creek,  Iowa.    X  2. 

23.  External  cast  of  the  dorsal  valves  showing  the  lamellose,  spineless 
surface. 

Jennings   formation,   Chemung  member,   Green   Glade  Run, 
near  Deer  Park. 


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PAGE 

Figs.  1-4.     DALMANELLA  TIOGA   (Hall) 569 

1.  Small  ventral  valve. 

2.  Cast  of  interior  of  ventral  valve. 

3.  Cast  of  interior  of  dorsal  valve  showing  muscular  scars. 

4.  Portion  of  surface  of  preceding.    X  4. 

Jennings    formation,    Chemung    member,    Ellerslie,    Penna. 
Figs.  1,  2,  at  1316.    Figs.  3,  4,  at  1474. 

Fig.  5.     DALMAXELLA  CARINATA  (Hall) 570 

Cast  of  interior  of  dorsal  valve.    Jennings  formation,  Chemung  mem- 
ber, west  of  Ellerslie,  Penna. 

Fig.  6.     DALMAXELLA  sp 572 

Ventral  valve.    X  3.    Jennings  formation,  Chemung  member,  National 
Road,  Polish  Mountain. 

Figs.  7-11.     RHIPIDOMELLA  VAXUXEMI  (Hall) 572 

7.  Ventral  valve.    Hill  south  of  Potomac  River,  2%  miles  southeast  of 

Cumberland. 

8,  9.  Ventral  and  dorsal  valves.     Hinge  line  is  shorter  and  cardinal 

angles  more  acute  than  in  fig.  7.    Same  locality. 

10.  Enlargement  of  interior  of  dorsal  valve   showing  hinge.      X  2. 

Williams  Road,  Polish  Mountain,  1371. 

11.  Cast  of  interior  of  ventral  valve  showing  muscular  scars.    Base  of 

Parkhead  member,  hill  south  of  Turners  Run  Road,  9  miles 
southeast  of  Cumberland. 
Jennings  formation,  Parkhead  member. 

Figs.  12,  13.     RHIPIDOMELLA  VAXUXEMI  VAR. 

12.  Ventral  valve. 

13.  Cast  of  interior  of  dorsal  valve. 

Jennings  formation,  base  of  Parkhead  member,  B.  &  O.  R.  R. 
cut,  Rocky  Run,  7  miles  southeast  of  Cumberland. 

Figs.  14-18.     SCHIZOPHOKIA   STRIATULA    (Schlotheim) 572 

14.  Cast  of  interior  of  ventral  valve  of  an  unusually  large  individual 

showing  deep  muscular  scars.     Western  Maryland  Railroad,  2 
miles  west  of  Pawpaw,  1300. 

15.  Cast  of  interior  of  ventral  valve.    Same  locality  as  preceding. 

16.  Cast  of  interior  of  dorsal  valve,  preserving  striae.    Yellow  Springs 

Road,  3  miles  east  of  Berkeley  Springs,  West  Virginia,  660  feet 
west  of  beginning  of  section. 

17.  Cast  of  interior  of  dorsal  valve.    National  Road,  west  of  Tonoloway 

Ridge. 

18.  Cast   of    interior   of  ventral   valve    of   young   individual.      Same 

locality  as  fig.  16.    310  feet  west  of  beginning  of  section. 
Jennings  formation,  Woodmont  member,  Ithaca  fauna. 


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PLATE  LIII 

PAGE 

Fig.  1.     SCHIZOPHOBIA  STRIATULA   ( Schlotheim) 572 

Cast  of  interior  of  ventral  valve  which  approaches  the  next  variety. 
Jennings  formation,  Chemung  member,  Ellerslie,  Penna.,  1474. 

FigS.    2-9.      SCHIZOPHORIA   STRIATULA  VAR.   MARYLANDICA  n.    Var 574 

2-4.  Internal  casts  of  dorsal  valves. 
5.  Internal  cast  of  ventral  valve. 
6-8.  Three  ventral  valves. 
9.  Dorsal  valve. 

Jennings  formation,  Chemung  member,  Deer  Park  and  vi- 
cinity. 

Fig.  10.     SCHIZOPHORIA  STRIATULA  (Schlotheim)  ? 572 

Internal  cast  of  ventral  valve.    Jennings  formation,  Parkhead  mem- 
ber, Rocky  Run,  7  miles  southeast  of  Cumberland. 

Figs.  11-16.     CAMAROTCECHIA  CONGREGATA  VAR.  PARKHEADENSIS  n.  var 575 

11.  Ventral   valve    more   elongate   than    usual.      Parkhead    member, 

National  Road,  east  of  Hancock,  1600. 

12.  Cast  of  interior  of  ventral  valve.    Associated  with  fig.  11. 

13.  Dorsal  valve.    Associated  with  preceding. 

14.  Posterior  view  of  cast  of  interior.     Chemung  member,  National 

Road,  Polish  Mountain  above  7th  turn. 

15.  Cast  of  interior  of  dorsal  valve.    Associated  with  fig.  14. 

16.  Cast  of  interior  of  ventral  valve.    X  2.    Associated  with  preceding. 

17.  Cast  of  interior  of  ventral  valve  approaching  C.  sappho  in  form. 

Base  of  Parkhead  member,  road  1  mile  north  of  Rocky  Run.  6 
miles  southeast  of  Cumberland. 
Jennings  formation. 

Figs.  18-20.     CAMAROTCECHIA  CONTRACTA   (Hall) 577 

18.  Ventral  valve  of  typical  form  showing  sharp  angular  plications. 

Allegany  Grove,  2957. 

19.  20.  Ventral  valves  possessing  less  angular  plications,  approaching 

C.  congregata  var.  parkheadensis.    National  Road,  Polish  Moun- 
tain, above  7th  turn. 

Jennings  formation,  Chemung  member. 

Fig.  21.     CAMAROTCECHIA  CONTRACTA  (Hall)  var 577 

Cast  of  interior  of  ventral  valve.    Jennings  formation,  Chemung  mem- 
ber, National  Road,  east  of  Millstone,  3116. 

Figs.  22-25.     CAMAROTCECHIA  HORSFORDI    (Hall) 578 

22.  Ventral   valve,    doubtfully   referred    to   this   species.     Chemung 

member,  National  Road,  Polish  Mountain  above  7th  turn. 

23,  24.  Cast  of  interiors  of  ventral  and  dorsal  valves.    Parkhead  mem- 

ber.   2%  miles  north  of  mouth  of  Sideling  Hill  Creek,  1700. 

25.  Anterior  view  of  shell.     Parkhead  member,  Western  Maryland 

Railroad,  2  miles  west  of  Pawpaw. 
Jennings  formation. 

Figs.  26,  27.     CAMAROTCECHIA  ORBICULARIS   (Hall) 579 

26.  Cast  of  interior  of  dorsal  valve.    2%  miles  southwest  of  Mountain 

Lake  Park. 

27.  Side  view  of  dorsal  valve.     Jennings  Run  Road,  1  mile  east  of 

Barrelville. 

Jennings  formation,  Chemung  member. 

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PLATE  LIV 

PAG0 

Figs.  1-4.     CAMAROTCECHIA  EXIMIA  (Hall) 579 

1.  Ventral  valve.    Town  Creek,  4596. 

2.  Cast  of  interior  of  ventral  valve.    Allegany  Grove,  1860. 

3.  Cast  of  interior  of  dorsal  valve.     Western  Maryland  Railroad,  2 

miles  west  of  Pawpaw,  4703. 

4.  Anterior  view  showing  slight  development  of  sinus.     X  2.     Town 

Creek,  4596. 
Jennings  formation,  Chemung  member. 

Figs.  5-8.     LIORHYNCHUS  MESACOSTALE  Hall 581 

5.  Ventral  valve. 

6.  Cast  of  interior  of  ventral  valve. 

7.  Cast  of  interior  of  ventral  valve  of  young  individual. 

8.  Cast  of  interior  of  ventral  valve  of  a  somewhat  crushed  individual. 

Jennings  formation,  Parkhead  member,  Williams  Road,  3% 
miles  east  of  Cumberland,  1393. 

Fig.  9.     LIORHYNCHUS  CF.  MUI/TICOSTUM  Hall 581 

Exterior  of  ventral  valve.  Jennings  formation,  Parkhead  member  (?), 
National  Road,  west  side  of  Green  Ridge. 

Figs.  10-16.     LIORHYNCHUS  GLOBULIFORME  (Vanuxem) 582 

10-12.  Dorsal,  anterior  and  ventral  views  of  an  internal  cast  of  an 
unusually  elongate  individual.  Yellow  Springs  Road,  3  miles 
east  of  Berkeley  Springs,  W.  Va.,  1124. 

13.  Enlargement  of  muscular  scars  and  hinge  of  ventral  valve.     X  3. 

National  Road,  east  of  Millstone,  1122. 

14.  Cast  of  interior  of  dorsal  valve  of  usual  form.    Western  Maryland 

Railroad,  2  miles  west  of  Pawpaw,  1300. 

15.  Enlargement  of  hinge  and  muscular  scars  of  fig.  14.    X  4. 

16.  Cast  of  interior  of  dorsal  valve.    Locality  not  known. 

Jennings  formation,  Woodmont  member,  Ithaca  fauna. 

Figs.  17-22.     PUGNAX  PUGNUS  VAR.  ALTUS  Calvin 583 

17-19.  Ventral,  dorsal  and  side  views  of  internal  cast.    Woodmont,  1000. 

20.  Cast  of  interior  of  a  dorsal  valve  bearing  more  pronounced  angular 

plications. 

21.  Enlargement  of  muscular  scars  and  hinge  of  ventral  valve.     X  3. 

Same  locality  as  figs.  17-19. 

22.  Enlargement  of  hinge  of  dorsal  valve.     X  3.    Yellow  Springs  Run 

Road,  3  miles  east  of  Berkeley  Springs,  West  Virginia,  510  feet 
west  of  beginning  of  section. 
Jennings  formation,  Woodmont  member,  Ithaca  fauna. 

Fig.  23.     CRYPTONELLA  CF.  EUDORA  Hall 584 

Internal  cast  of  a  ventral  valve.  Jennings  formation,  Chemung  mem- 
ber (?),  Williams  Road,  Polish  Mountain. 


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21 


10 


14 


18 


11 


10 


iMH 


22 


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12 


16 


20 


23 


PLATE  LV 

PAGE 

Figs.  1-5.     TROPIDOLEPTUS  CARINATUS  (Conrad) 585 

1.  Ventral  valve.    Williams  Road,  3%  miles  east  of  Cumberland,  1466. 

2.  Cast  of  interior  of  ventral  valve.     Sideling  Hill  Creek,  2%  miles 

above  mouth,  1700. 

3.  Dorsal  valve.    Two  miles  north  of  mouth  of  Town  Creek,  1949. 

4.  Interior  of  dorsal  valve.    Same  locality  as  preceding  specimen. 

5.  Enlargement  of  hinge  of  fig.  4.    X  4. 

Jennings  formation,  Parkhead  member. 

Figs.  6-11.     ATRYPA  RETICULARIS  (Linne") 586 

6.  Ventral  valve  showing  alation  about  margin  unusually  well.     Jen- 

nings formation,  Woodmont  member,  Ithaca  fauna,  National 
Road,  east  of  Hancock,  690. 

7.  Enlargement  of  hinge  of  cast  of  interior  of  ventral  valve.     X  2. 

Same  specimen  as  fig.  6. 

8.  Enlargement  of  hinge  of  cast  of  interior  of  dorsal  valve.     X  3.    2y2 

miles  northeast  of  Pratt. 

9.  Cardinal  region  of  the  dorsal  valve  enlarged,  showing  the  crenulate 

dental  sockets.    Polish  Mountain. 

10.  Ventral  valve  retaining  parts  of  concentric  lamellae.     Near  Deer 

Park. 

11.  Ventral  valve.    Oakland. 

Jennings  formation,  Chemung  member. 

Figs.  12,  13.     ATRYPA  SPINOSA  Hall 587 

12.  Ventral  valve. 

13.  Cast  of  interior  of  dorsal  valve. 

Jennings  formation,  Chemung  member,  Ellerslie,  Penna,,  1524. 

Figs.  14-19.     ATRYPA    HYSTRIX    Hall 589 

14.  A  young  ventral  valve.    National  Road,  5  miles  west  of  Frostburg. 

15.  Cast  of  interior  of  ventral  valve  with  very  coarse  plications.     % 

mile  southwest  of  Gortner. 

16.  Ventral  valve.    Trout  Creek,  Oakland. 

17.  Dorsal  valve.    Near  Oakland. 

18.  Enlargement  of  surface  showing  the  lamellae  enfolding  into  spines. 

X  2. 

19.  Ventral  valve.    Trout  Creek,  Oakland. 

Jennings  formation,  Chemung  member. 


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PLATE  LVI 

PAGE 

Figs.  1-3.     CYRTINA  HAMJ.LTONENSIS  Hall 591 

1.  Cast  of  interior  of  ventral  valve.     Chemung  member,  road  from 

Oakland  to  Deer  Park. 

2.  Cast  of  interior  of  ventral  cardinal  area.    Same  locality. 

3.  Dorsal  valve.     X  2.     Woodmont  member,  Ithaca  fauna,  National 

Road,  west  of  Tonoloway  Ridge. 
Jennings  formation. 

Figs.  4-6.     RETICULARIA  L^EVIS   (Hall) 592 

4.  Cast  of  interior  of  dorsal  valve. 

5.  Interior  of  ventral  valve.     Portage  formation,  New  York. 

6.  Cast  of  interior  of  ventral  valve  showing  muscular  scars. 

Jennings  formation,  Woodmont  member,  Ithaca  fauna,  Na- 
tional Road,  east  of  Hancock,  690. 

Figs.  7-14.     SPIBIFEB  DISJTJNCTUS  Sowerby 593 

7.  Ventral  valve.    National  Road,  Polish  Mountain. 

8,  9.  Ventral  valves.    Near  Deer  Park. 

10.  Ventral  valve  with  extended  cardinal  angles.    National  Road,  near 

top  of  Polish  Mountain. 

11.  Ventral  valve  with  extended  cardinal  angles.    Near  Deer  Park. 

12.  Interior  of  dorsal  valve.    Near  Oakland. 

13.  Internal  cast  of  ventral  valve.    National  Road,  Polish  Mountain. 

14.  Enlargement  of  cardinal  portion  of  internal  cast  of  ventral  valve. 

X  2.    Town  Creek,  2122. 
Jennings  formation,  Chemung  member. 


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PAGE 

Fig.  1.     SPIKIFEB  DISJUNCTUS  Sowerby 593 

Internal  cast  of  conjoined  valves  with  extremely  extended  cardinal 
angles.    Jennings  formation,  Chemung  member,  near  Deer  Park. 

Figs.  2-5.     SPIRIFEB  MESASTEIALIS  Hall 596 

2.  Cast  of  interior  of  ventral  valve.    Near  Pawpaw,  W.  Va. 

3.  Cast  of  interior  of  dorsal  valve.    National  Road,  east  of  Millstone, 

2444. 

4.  Enlargement  of  portion  of  surface  of  dorsal  valve.     Wills  Creek 

Station,  Penna. 

5.  Dorsal  valve.    National  Road,  east  of  Millstone. 

Jennings  formation,  Chemung  member. 

Figs.  6-10.     SPIKIFEB  MARCYI  VAR.  SUPERSTES  n.  var 597 

6.  Portion  of  cast  of  interior  of  dorsal  valve,  enlarged  X  2,  showing 

muscular  scars  and  hinge.    B.  &  O.  Railroad  cut,  Rocky  Run,  7 
miles  southeast  of  Cumberland. 

7.  Enlargement  of  a  portion  of  surface  showing  granulose  plications. 

X  5.    National  Road,  Polish  Mountain. 

8.  Cast  of  interior  of  dorsal  valve.    National  Road,  Polish  Mountain, 

above  sixth  turn. 

9.  Cast  of  interior  of  dorsal  valve  with  shorter  wings.    National  Road 

on  Green  Ridge,  2690. 

10.  Posterior  view  showing  cardinal  area  of  ventral  valve  with  partially 

filled  delthyrium.    Associated  with  fig.  9. 

11.  Posterior  view  of  cast  of  interior  of  ventral  valve  showing  strength 

of  dental  plates.    Associated  with  fig.  9. 

Jennings  formation,  Figs.  6,  7  from  near  base  of  Parkhead 
member,  Figs.  8-11  from  Chemung  member. 


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PAGE 

Figs.  1-10.     SPIRIFER  MUCRONATUS  VAR.  POSTERUS  Hall  and  Clarke 599 

1.  Ventral  valve  of  medium  size.     National  Road,  east  of  Hancock, 

1149  to  1274. 

2.  Dorsal  valve  with  extended  cardinal  angles.    National  Road,  west 

of  Tonoloway  Ridge. 

3.  Dorsal  valve.    Associated  with  fig.  2. 

4.  Cast,  of  interior  of  a  very  large  dorsal  valve.    Woodmont,  1032. 

5.  Cast  of  interior  of  ventral  valve  of  medium  size.     There  is  no 

median  septum  but  muscular  scar  is  divided  by  an  impressed 
line.  Yellow  Springs  Road,  3  miles  east  of  Berkeley  Springs,  660 
feet  west  of  beginning  of  section. 

6.  Cast  of  interior  of  large  ventral  valve  with  greatly  extended  ex- 

tremities.   Woodmont,  1032. 

7.  Cast  of  interior  of  dorsal  valve   differing  from   prevailing  form. 

Woodmont,  1000. 

8.  Enlargement  of  cast  of  interior  of  dorsal  valve  showing  muscular 

scars.  X  3.  Western  Maryland  Railroad,  2  miles  west  of 
Pawpaw,  1300. 

9.  Cast  of  interior  of  ventral  valve  of  young  individual.     National 

Road,  east  of  Hancock,  690. 

10.  Enlargement  of  a  portion  of  exterior  of  valve  of  young  individual 
showing  ornamentation.  X  10.  National  Road,  east  of  Mill- 
stone, 795. 

Jennings  formation,  Woodmont  member,  Ithaca  fauna. 

Figs.  11-23.     SPIRIFER   (DELTHYRIS)   MESACOSTALIS  Hall 601 

11.  Ventral  valve  of  a  very  small  individual.    Near  Deer  Park. 

12.  A  larger  ventral  valve.    National  Road,  Polish  Mountain. 

13.  Enlargement  of  a  part  of  surface  of  ventral  valve  showing  median 

rib  and  sharp  lamellose  concentric  markings.  X  2.  Same 
locality. 

14.  Small  dorsal  valve.    Same  locality. 

15.  Small  ventral  valve.    X  2.    The  ribs  are  made  to  appear  too  sharp 

and  the  concentric  lines  too  angular.    Near  Pawpaw,  W.  Va. 

16.  Small  dorsal  valve.    Near  Deer  Park. 

17, 18.  Cast  of  interior  of  small  ventral  valves.    X  2.    Same  locality. 

19.  Cast  of  interior  of  small  dorsal  valve.     X  2.    Same  locality. 

20.  Cast  of  interior  of  ventral  valve.    Mountain  Lake  Park. 

21.  22.  Cast  of  interiors  of  ventral  and  dorsal  valves  of  usual  size. 

Williams  Road,  Polish  Mountain,  1660. 

23.  Cast  of  interior  of  large  ventral  valve  having  extended  cardinal 
angles.    4700  feet  northeast  of  Sunnyside. 

Jennings  formation,  figs.  21,  22  Parkhead  member,  balance 
Chemung  member. 


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PAGE 

Figs.  1,  2.     SPIBIFEB  (DELTHYRIS)  MESACOSTALIS  Hall 601 

1.  Cast  of  interior  of  large  dorsal  valve  with  greatly  extended  cardinal 

angles.    1  mile  southeast  of  Sunnyside. 

2.  Cast  of  interior  of  ventral  valve  of  usual  size.    X  2.    National  Road, 

Polish  Mountain. 
Jennings  formation,  Chemung  member. 

Figs.  3-7.     AMBOCCELIA  UMBONATA   (Conrad) 602 

3.  Ventral  valve.    X  2.    Polish  Mountain. 

4.  Dorsal  valve.    X  2.    Same  locality. 

5.  Internal  cast  of  dorsal  valve.    X  2.    Same  locality. 

6.  Exterior  of  ventral  valve.    X  2.    Same  locality. 

7.  Internal  cast  of  ventral  valve.    X  2.    Near  Deer  Park. 

Jennings  formation,  Chemung  member. 

Figs.  8-10.     ATHYRIS  ANGELICA  Hall 604 

8.  Dorsal  valve. 

9, 10.  Ventral  valves. 

Jennings  formation,  Chemung  member,  Allegany  Grove,  2941. 

Figs.  11,  12.     GRAMMYSIA  EIXIPTICA  Hall 606 

Two  views  of  a  right  valve.  Jennings  formation,  Chemung  member,  1 
mile  east  of  Barrelville. 

Fig.  13.     GRAMMYSIA  SUBARCUATA  Hall 606 

Left  valve.    Chemung  formation,  New  York. 

Figs.  14,  15.     GRAMMYSIA  COMMXTNIS  Hall 607 

Right  and  left  valves.  Jennings  formation,  Woodmont  member,  Ithaca 
fauna,  Yellow  Springs  Run  Road,  3  miles  east  of  Berkeley 
Springs,  W.  Va.,  1124. 

Figs.  16,  17.     PAL^ANATINA  ANGUSTA 609 

16.  A  small  right  valve. 

17.  Cast  of  interior  of  right  valve. 

Jennings  formation,  Chemung  member,  Town  Creek,  4596. 

Figs.  18,  19.     SPHENOTUS  CONTRACTUS  Hall 610 

18.  Sculpture  cast  of  left  valve.    Chemung  formation,  New  York. 

19.  Right  valve  doubtfully  determined.    Jennings  formation,  Chemung 

member,  Wills  Creek  Station,  Penna. 


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15 


17  18  19 

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PLATE  LX 

VAGE 
FigS.    1-3.      BUCHIOLA  RETROSTRIATA    (V.   Buch) 613 

1.  A  large  right  valve,  somewhat  flattened.     X  3.    Barrelville  Road,  y2 

mile  west  of  Corriganville. 

2.  A  very  small  right  valve  with  few  broad  flat  ribs  with  coarse  re- 

curved surface  markings.     X  5.    Town  Creek,  Gilpin. 

3.  An  enlargement  showing  the  smooth  embryo  shell  and  the  abrupt 

introduction  of  the  radial  ornament  in  secondary  growth,    x  10. 
Wolfe  Mills,  near  Cumberland. 

Jennings  formation,  Genesee  member. 
Figs.  4-6.     BUCHIOLA  CONVERSA  Clarke 615 

4.  Right  valve  of  type  showing  the  elevated  margins  and  concave  sur- 

face of  the  ribs.     X  3.    Lower  Falls  of  the  Genesee  River,  New 
York.    Naples  shales. 

5.  6.  Left  and  right  valves.     X  5. 

Jennings  formation,  Woodmont  member,  Naples  fauna,  Town 
Creek,  Gilpin. 
Figs.  7,  8.     BUCHIOLA  MARI.E  n.  sp 615 

7.  Right  valve.    X  4. 

8.  Smaller  right  valve.     X  3. 

Jennings  formation,  Genesee  member,  Williams  Road,  Cum- 
berland. 

Figs.  9-12.     BUCHIOLA  ?  LIVONIA  Clarke 616 

9.  Right  valve  showing  the  numerous  flattened  ribs.  X  4.  Jennings 
formation,  Woodmont  member,  Naples  fauna,  National  Road, 
east  of  Town  Creek,  Gilpin. 

10.  The  two  valves,  normally  expanded.     Romney  Road,   3%  miles 

southeast  of  Burlington,  W.  Va.  Jennings  formation,  Genesee 
member. 

11.  Right  valve.    X  4.    Same  locality  as  fig.  10. 

12.  Left  valve  of  the  type  specimen  showing  the  fine  concentric  linea- 

tion  of  ribs.    X  3.    Styliola  limestone  of  Genesee  shales,  Livonia 
salt  shaft,  New  York. 
Figs.  13-16.     PARACARDIUM  DORIS  Hall 617 

13.  A  small  right  valve.     X  4.    Wolfe  Mills,  near  Cumberland. 

14.  Both  valves.    X  4!    Wolfe  Mills,  near  Cumberland. 

15.  A  large  right  valve.     X  4.    West  of  Corriganville. 

16.  The  right  valve.    X  4.    Same  locality  as  fig.  15. 

Jennings  formation,  Genesee  member. 
Figs.  17,  18.     PARACARDIUM  DELICATULUM  Clarke 618 

17.  A  valve  with  normal  characters,  somewhat  deformed  about  the 

hinge.  X  10.  This  is  the  type  specimen.  Styliola  limestone  of 
the  Genesee  shale  (Naples  fauna).  Canandaigua  Lake,  New 
York. 

18.  A  right  valve  showing  the  extremely  fine  radial  ribs,  which  are 

crossed  by  concentric  lines,  though  these  are  made  much  too 
strong  in  the  drawing.  X  10. 

Jennings  formation,  Genesee  member,  Wolfe  Mills,  near  Cum- 
berland. 
Figs.  19-23.     NUCULA  CORBULIFORMIS  Hall.  .  , 619 

19.  Cast  of  interior  of  left  valve.     X  2.     Woodmont  member,  Ithaca 

fauna,  National  Road,  west  of  Tonoloway  Ridge. 

20.  Cast  of  interior  of  left  valve.     X  2.     Woodmont  member,  Ithaca 

fauna,  same  locality  as  fig.  19. 

21.  Enlargement  of  portion  of  exterior.     X  8.     Woodmont  member, 

Ithaca  fauna,  Berkeley  Springs,  West  Virginia,  1058. 

22.  Right  valve.    Parkhead  member,  2  miles  north  of  mouth  of  Town 

Creek,  1716. 

23.  Enlargement  of  cast  of  interior  showing  hinge.    Parkhead  member, 

Williams  Road,  Polish  Mountain,  1352. 
Jennings  formation. 

Fig.  24.     PAL^ONEILO  PETILA  Clarke  ? 624 

Right  valve.     X  2.     Jennings  formation,  Woodmont  member,  Naples 
fauna,  Williams  Road,  3%  miles  east  of  Cumberland,  406. 

Fig.  25.     PAL^EONEILO  MAXIMA  (Conrad)  ? 622 

Cast  of  interior  of  right  valve.     2  miles  north  of  mouth  of  Town 
Creek,  Parkhead  member,  1282. 
Jennings  formation. 

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22 


:   ^V 


18 


11 


13 


19 


20 


23  24 

MOLLUSCA — PELECYPODA 


12 


18 


25 


PLATE  LXI 

PAGE 

Figs.  1-3.     PAL^ONEILO  PLANA  Hall 621 

1.  Cast  of  interior  of  left  valve.    National  Road,  east  of  Millstone,  2322. 

2.  Left  valve.    Associated  with  preceding. 

3.  Cast  of  interior  of  a  very  elongate  left  valve  probably  of  this  species. 

Near  Mr.   Cheney's,  2%  miles  northeast  of  Pratt,  at  base  of 
section. 

Jennings  formation,  Chemung  member. 

Figs.  4-6.     PAI/^EONEILO  BREVIS  Hall 622 

4.  5.  Casts  of  interiors  of  right  and  left  valves.     Parkhead  member, 

Western  Maryland  Railroad,  2  miles  west  of  Pawpaw,  1763. 

6.  Cast  of  interior  of  left  valve.     Woodmont  member,  Ithaca  fauna, 

Woodmont. 

Jennings  formation. 

Figs.  7-10.     PAi/y£ONEiix>  CONSTRICTA   (Conrad) 620 

7.  Cast  of  interior  of  right  valve.     Jennings  formation,  Woodmont 

member,  Ithaca  fauna,  Woodmont,  710. 
8,9.  Sculpture  casts  of  right  and  left  valves.     Hamilton  formation, 

western  New  York. 

10.  Cast  of  left  valve.     Jennings  formation,  Chemung  member,  Green 
Ridge. 

Figs.  11,  12.     PAL^ONEILO  FILOSA   (Conrad) 623 

Two  right  valves.    X  2.    Jennings  formation,  Chemung  member,  near 
Wills  Creek  Station,  Penna. 

Fig.  13.     PAI^EONEILO  ANGUSTA  Hall 624 

Left  valve.    Jennings  formation,  Chemung  member,  1  mile  southeast 
of  Sunnyside. 

FigS.    14,    15.      PALyEONEILO  CKASSA  n.  Sp 625 

14.  Cast  of  interior  of  right  valve  of  type. 

15.  Dorsal  view  of  internal  cast. 

Jennings  formation,  Chemung  member,  Town  Creek,  3584. 

Figs.  16,  17.     LEDA  CF.  DIVERSA  Hall 626 

16.  Cast  of  interior  of  left  valve.    X  2.    Town  Creek,  3760. 

17.  Cast  of  interior  of  left  valve.     X  2.    Town  Creek,  3870. 

Jennings  formation,  Chemung  member. 

Fig.  18.     MACRODON  CHEMUNGENSIS  Hall 627 

Cast  of  interior  of  left  valve.    Jennings  formation,  near  base  of  Park- 
head  member,  White  Sulphur  Branch,  4  miles  southeast  of  Pratt. 

Figs.  19-21.     PTERINEA  NODOCOSTA  n.  sp 628 

19.  A  large  left  valve  showing  the  coarse  nodose  ribs  and  finer  inter- 

vening ones.    Oakland. 

20,  21.  Two  rather  imperfect  and  small  left  valves.    Near  Deer  Park 

and  Oakland. 

Jennings  formation,  Chemung  member. 

Fig.  22.     PTERINEA  CHEMUNGENSIS  (Conrad ) 629 

22.  A  left  valve  of  normal  character.    Jennings  formation,  Chemung 
member,  National  Road,  7  miles  west  of  Frostburg. 


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PLATE  LXII 

PAGE 

Figs.  1-3.    LUNULICARDIUM  ENCRiNiTUM  Clarke 630 

1.  Left  valve  showing  the  finely  lineate  surface.     X  3.     Town  Creek, 

Gilpin,  Allegany  County. 

2.  Same.    X  2.    Wolfe  Mills,  near  Cumberland. 

3.  Same.    X  3.    Allegany  County. 

Jennings  formation,  Genesee  member. 

Fig.  4.     LUNULICARDIUM  CYMBULA  n.  sp G31 

The  single  valve  observed.     X  5.    Jennings  formation,  Genesee  mem- 
ber, near  Corriganville. 

Figs.  5-7.     PTEROCH^NIA  FRAGILIS   (Hall) 632 

5.  Right  valve  showing  the  smooth  concentrically  lined  surface  and 

the  sica.    X  3.    Jennings  formation,  Woodmont  member,  Naples 
fauna,  Town  Creek,  Gilpin. 

6,  7.  Right  and  left  valves.     X  3.    Jennings  formation,  Genesee  mem- 

ber, west  of  Corriganville. 

FigS.    8,    9.      ECTENODESMA    BIROSTRATUM    Hall 633 

8.  Cast  of  interior  of  left  valve.     The  wings  of  this  specimen  are 

broken.    Jennings  formation,  Woodmont  member,  Ithaca  fauna, 
Little  Orleans,  Wagon  Road,  north  of  Western  Maryland  R.  R. 

9.  Left  valve.    Chemung  formation,  New  York. 

Figs.  10-12.     LIOPTERIA   BIGSBYI   Hall 634 

10, 11.  Left  and  right  valves.     Hamilton  or  Ithaca,  Schoharie,  New 

York. 

12.  Left  valve  doubtfully  referred  to  this  species.     Jennings  forma- 
tion, Chemung  member,  National  Road,  Polish  Mountain,  2714. 

Figs.  13,  14.     LIOPTERIA  MARYLAXDICA  n.  sp 635 

Casts  of  interior  of  two  left  valves.     Jennings  formation,  Chemung 
member,  Town  Creek,  2023. 


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PAGE 

Fig.  1.     LIOPTERIA  AURICULATA  n.  sp 636 

Exterior  of  left  valve.  The  anterior  ear  is  made  too  large  in  drawing. 
Jennings  formation,  Woodmont  member,  Ithaca  fauna,  National 
Road,  east  of  Millstone,  795. 

Fig.  2.     LIOPTEBIA  sp. 

A  small  suberect  left  valve  with  short  posterior  wing  and  concen- 
trically lined  surface.  Jennings  formation,  Chemung  member, 
Trout  River,  2  miles  south  of  Oakland. 

Fig.  3.     LEPTODESMA  ROGERSI  Hall 636 

Right  and  left  valves.    Ithaca  beds,  Norwich,  N.  Y. 

Figs.  4-8.     LEPTODESMA  LONGISPINUM  Hall 637 

4.  Right  valve.    Chemung  formation,  New  York. 

5.  Left  valve  with  posterior  spine  restored.    Near  Oakland. 

6.  Left  valve  doubtfully  referred  to  this  species.     National  Road,  6 

miles  west  of  Frostburg. 

7.  8.  Right  and  left  valves.    Same  locality. 

Jennings  formation,  Chemung  member. 

Figs.  9,  10.     LEPTODESMA  AGASSIZI  Hall 637 

9.  Left  valve. 

10.  Right  valve. 

Chemung  formation,  New  York. 

Figs.  11-15.     LEPTODESMA  MEDON  Hall 638 

11.  Small  left  valve.    National  Road,  7  miles  west  of  Frostburg. 
12, 13.  Right  valves.    Allegany  Grove,  2307. 

14, 15.  Left  valves.    Allegany  Grove,  about  2215. 
Jennings  formation,  Chemung  member. 

Figs.  16,  17.     LEPTODESMA  NAVIFORME  Hall 639 

16.  Exterior  of  large  right  valve  showing  faint  radiating  striae. 

17.  Exterior  of  right  valve  of  somewhat  different  proportions. 

Jennings  formation,  near  base  of  Parkhead  member,  Williams 
Road,  4  miles  east  of  Cumberland. 

Figs.  18,  19.     LEPTODESMA  LICHAS  Hall 640 

18.  Left  valve.    Jennings  formation,  Chemung  member,  National  Road, 

6  miles  west  of  Frostburg. 

19.  Left  valve.    Chemung  formation,  New  York. 

Fig.  20.     LEPTODESMA  ELONGATUM  n.  sp 640 

Left  valve.  Jennings  formation,  near  top  of  Chemung  member,  Keyser- 
Piedmont  Road,  2%  miles  west  of  Keyser,  W.  Va. 

Fig.  21.     GOSSELLETIA  sp 641 

Cast  of  interior  left  valve.  Jennings  formation,  Chemung  member, 
Williams  Road,  Polish  Mountain. 


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11 


21 


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PLATE  LXIV 

PAGE 
Fig.    1.      ACTINOPTERIA   CF.   EPSILON   Hall 642 

A  large  left  valve,  showing  radial  lines.    Ithaca  beds,  Ithaca,  N.  Y. 

Fig.  2.     ACTINOPTERIA  BOYDI    (Conrad) 642 

Left  valve,  outline  restored.    Jennings  formation,  Woodmont  member, 
Ithaca  fauna,  Woodmont,  1170. 

Figs.  3-5.     SCHIZODUS  CHEMUNGENSIS   (Conrad) 644 

3,  4.  Casts  of  interior  of  right  valve. 
5.  Cast  of  interior  of  left  valve. 

Jennings  formation,  Chemung  member,  Town  Creek,  3453. 

Fig.  6.     SCHIZODUS  CHEMUNGENSIS  VAK.  QUADRANGULARIS  Hall 645 

Left  valve.    Jennings  formation,  Chemung  member,  near  Deer  Park. 

Figs.  7-14.     SCHIZODUS  OHERNI  n.  sp 646 

7.  Left  valve. 

8.  Cast  of  interior  of  right  valve  of  more  circular  shape  than  usual. 
9, 10.  Interior  of  left  and  right  valves  showing  hinge. 

11.  Cast  of  interior  of  right  valve. 

Jennings  formation,  Parkhead  member,  National  Road,  east 
of  Millstone,  1781. 

12, 13.  Cast  of  interior  of  very  large  left  valves. 
14.  Posterior  view  of  cast  of  valve  shown  in  fig.  13. 

Jennings  formation,  Chemung  member,  Sideling  Hill  Creek. 

Fig.  15.     SCHIZODUS  FROSTBURGENSIS  n.  sp 647 

Cast  of  interior  of  left  valve.    Jennings  formation,  Chemung  member. 
National  Road,  7  miles  west  of  Frostburg. 

Figs.  16-18.     SCHIZODUS  TRIGONALIS  n.  sp 647 

16-17.  Casts   of  interiors   of  left  valves.     Chemung   member,   Town 

Creek,  2228. 

18.  Cast  of  interior  of  right  valve,  probably  of  this  species.    Parkhead 
member,  National  Road,  east  of  Millstone,  1781. 
Jennings  formation. 


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PLATE  LXV 

PAGE 

Fig.  1.     LYRIOPECTEN  TRICOSTATUS  (Vanuxem) 649 

Left  valve  with  characteristic  surface  markings.    Jennings  formation, 
Chemung  member,  Allegany  County,  near  West  Virginia  line. 

Pig.  2.     MODIOMORPHA  SUBANGULATA  Hall  var 650 

Right  valve.    Jennings  formation,  Chemung  member,  Williams  Road, 
Polish  Mountain,  2382. 

Fig.    3.      GONIOPHORA  HAMILTONENSIS  Hall 651 

Left  valve.     Jennings  formation,  Parkhead  member,  Western  Mary- 
land Railroad,  2  miles  west  of  Pawpaw,  1485. 

Figs.  4-6.     GONIOPHORA  TRUNCATA  Hall 651 

4.  Cast  of  interior  of  left  valve. 

5.  Cast  of  interior  of  right  valve. 

6.  Left  valve. 

Jennings  formation,  Parkhead  member,  Williams  Road,  Polish 
Mountain,  1660. 

Fig.  7.     GONIOPHORA  GLAUCA  Hall 652 

Right  valve.     Jennings  formation,  base  of  Parkhead  member,  White 
Sulphur  Branch,  4  miles  southeast  of  Pratt. 

Figs.  8-10.     CYPRICARDELLA  BELLISTRIATA   (Conrad) 653 

8.  Left  valve. 

9.  Right  valve. 
10.  Left  valve. 

Hamilton  formation,  New  York. 

Figs.  11-15.     CYPRICARDELLA  MARYLANDICA  n.  sp 654 

11.  Right  valve. 

12.  Right  valve  somewhat  distorted. 

13.  Internal  cast  of  right  valve. 

14.  Left  valve  of  normal  outline. 

15.  Right  valve  expressing  the  correct  characters  of  the  exterior.    X  2. 

Jennings  formation,  Chemung  member,  Deer  Park. 

Figs.  16-18.     CYPRICARDELLA  GREGARIA  (Hall) 654 

Internal  casts  of  left  valves.    Jennings  formation,  Parkhead  (?)  mem- 
ber, National  Road,  west  of  Green  Ridge. 


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15 


PLATE  LXVI 

PAGE 

Figs.  1-5.     CYPRICABDELLA  TENUISTRIATA   (Hall) 656 

1.  Cast  of  interior  of  left  valve.    Sideling  Hill  Creek,  2y2  miles  above 

mouth,  1700. 

2.  Right  valve.    Two  miles  north  of  mouth  of  Town  Creek,  1716. 

3.  Right  valve,  somewhat  questionably  referred  to  this  species,  upon 

which  concentric  striae  of  umbo  are  nearly  obsolete.    Two  miles 
north  of  mouth  of  Town  Creek,  1632. 
Jennings  formation,  Parkhead  member. 

4.  Large  left  valve.    Hamilton  formation,  New  York. 

Figs.  6-12.     CYPRICARDELLA  NITIDULA  n.  sp 656 

6.  Left  valve  showing  the  well  marked  umbonal  slope  and  strong 

concentric  ridges.    X  2. 

7.  Internal  cast  of  left  valve  showing  muscle  scars  and  hinge.    X  2. 

8.  Gutta-percha  squeeze  of  hinge  of  left  valve.    X  2. 

9, 10.  Two  left  valves  of  an  elongate  finely  lined  shell,  with  posterior 
umbonal  ridge  close  upon  the  margin.  These  shells  resemble  in 
outline  C.  tenuistriata  Hall  except  for  the  position  of  the  pos- 
terior ridge. 

11.  Gutta-percha  squeeze  showing  interior  of  right  valve.     X  2. 

12.  The  interior  of  a  small  left  valve  of  the  same  species. 

Jennings  formation,  Chemung  member,  figs.  6-11  Deer  Park, 
fig.  12  National  Road,  west  of  Frostburg. 

Fig.  13.     CYPRICARDELLA  CUMBERLAND!^  n.  sp 657 

Cast  of  interior  left  valve.  Jennings  formation,  Chemung  member, 
Allegany  Grove. 

Figs.  14-20.     CYPRICARDELLA  CRASSA  n.  sp 657 

14, 15.  Left  valves. 

16.  Cast  of  interior  of  right  valve. 

17.  Cast  of  interior  of  left  valve. 

18.  Right  valve. 

19.  Interior  of  right  valve. 

20.  Hinge  of  right  valve  enlarged  X  2. 

Jennings  formation,  Chemung  member,  National  Road,  east  of 
Millstone,  2761. 

Fig.  21.     CYPRICARDINIA  ELEGANS  n.  sp 659 

Left  valve  of  type.  Jennings  formation,  Chemung  member,  National 
Road,  300  feet  west  of  schoolhouse,  Belle  Grove. 

Figs.  22-24.     CYPRICARDINIA  ELEGANS  VAR.  ANGUSTA  n.  var 659 

22.  Cast  of  interior  of  left  valve. 

23.  Dorsal  view  of  internal  cast.    The  valves  are  not  equal  in  convexity 

as  the  figure  seems  to  indicate. 

24.  Right  valve. 

Jennings  formation,  Chemung  member,  Town  Creek,  3584. 

Fig.  25.     PARACYCLAS  MARYLANDICA  n.  sp 660 

Right  valve  of  type.  Jennings  formation,  Chemung  member,  Town 
Creek,  3870. 


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PAGE 

Figs.  1-3.     PLETJROTOMARIA  (GYKOMA)  CAPILLARIA  Conrad 661 

1.  Ventral  view  of  large  individual.     X  2.    Hamilton  formation,  New 

York. 

2.  Dorsal  view  of  small  shell.    Jennings  formation,  Parkhead  member, 

Sideling  Hill  Creek,  2%  miles  above  mouth,  1700. 

3.  Exterior  of  portion  of  shell  showing  ornamentation  and  slit  band. 

Associated  with  preceding. 

Fig.  4.     HOBMATOMA  BisTRiATA  n.  sp 663 

Dorsal  view  of  type.     X  2.     Jennings  formation,  Parkhead  member, 
Sideling  Hill  Creek,  2%  miles  above  mouth,  1700. 

FigS.    5-8.       ECTOMAHIA  MARYLANDICA  n.   SP 663 

5.  Dorsal  view  of  shell.    X  2.    The  apical  angle  is  too  large  in  drawing. 

Western  Maryland  Railroad,  2  miles  west  of  Pawpaw,  1597. 

6.  Dorsal  view  of  shell.     X  2.     Sideling  Hill  Creek,  2y2  miles  above 

mouth,  1700. 

7.  Dorsal  view  of  type  specimen.    Western  Maryland  Railroad,  2  miles 

west  of  Pawpaw,  1597. 

8.  Cast  of  exterior  of  shell.    The  apical  angle  is  much  too  small,  due  to 

cast.    Same  locality. 
Jennings  formation,  Parkhead  member. 

Figs.  9-12.     ECTOMARIA  ECCLESI.E  n.  sp 664 

9.  A  group  of  shells,  natural  size.    Near  Oakland. 

10.  Dorsal  view.     X  3.    Deer  Park. 

11.  Part  of  the  spiral  with  the  concentric  striae  obsolete.     X  5.    Near 

Oakland. 

12.  An  enlargement  of  part  of  the  spire  showing  the  surface  orna- 

mentation.    X  5.    Polish  Mountain. 
Jennings  formation,  Chemung  member. 

Figs.  13-16.     BELLEROPHON  NACTOIDES  n.  sp 665 

13-15.  Dorsal,  ventral,  and  side  views  of  cast  of  exterior.     National 

Road,  west  of  Tonoloway  Ridge. 
16.  Enlargement  of  portion  of  surface.     X  3.    Same  locality. 

Jennings  formation,  Woodmont  member,  Ithaca  fauna. 

Figs.  17-20.     BELLEROPHON  CLARKI  n.  sp 666 

17-18.  Dorsal  and  side  view  of  type  specimen.     X  1%.    Williams  Road, 
Polish  Mountain,  1660. 

19.  Dorsal  view.     Western  Maryland  Railroad,  2  miles  west  of  Paw- 

paw, 1597. 

20.  Enlargement  of  exterior  showing  ornamentation.     Polish  Moun- 

tain. 

Jennings  formation,  Parkhead  member. 

Figs.  21,  22.     BUCANOPSIS  M^RA   (Conrad) 667 

Dorsal  and  side  view  of  shell.    Chemung  formation,  New  York. 

Figs.  23-25.     STRAPAROIXUS  MARYLANDICUS  n.  sp 668 

23.  Internal  cast  of  type,  dorsal  view. 

24.  Lower  surface  of  specimen  illustrated  in  fig.  23,  showing  large 

umbilicus.    Sideling  Hill  Creek,  2%  miles  above  mouth,  1700. 

25.  Upper  view  of  small  shell.    Williams  Road,  Polish  Mountain,  1661. 

Jennings  formation,  Parkhead  member. 

Fig.  26.     PH^XEROTINUS  LAXUS  (Hall) 669 

Internal  cast.    Parkhead  member,  Sideling  Hill  Creek,  2V2  miles  above 
mouth,  1700. 

Figs.  27-29.     CYCLONEMA  COXCIXNUM  Hall 670 

27.  Dorsal  view  showing  ornamentation.     Chemung  member,  Town 

Creek,  2228. 

28.  Dorsal  view  of  smaller  specimen.     Parkhead  member,  Western 

Maryland  Railroad,  2  miles  west  of  Pawpaw,  1597. 

29.  Internal  cast.     Parkhead  member,  Sideling  Hill  Creek,  2l/2  miles 

above  mouth. 

Jennings  formation. 

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26 


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M  OLLU  SC  A — GASTROPODA 


24 


PLATE  LXVIII 

PAGE 

Figs.  1-4.     CYCLONEMINA  CRENULISTRIATA  n.  sp 671 

1.  Dorsal  view. 

2.  Portion  of  the  surface  of  a  shell  enlarged.     X  3. 

3.  Dorsal  view  of  individual  showing  great  thickness  of  the  shell. 

4.  Dorsal  view  showing  aperture.    Type. 

Jennings  formation,  Chemung  member,  Town  Creek,  2228. 

Fig.  5.     CYCLONEMINA  CKENUXJSTRIATA  VAR.  OBSOLESCENS  n.  var 672 

Shell  preserving  portion  of  test,  showing  ornamentation.     Jennings 
formation,  Chemung  member,  Town  Creek,  2228. 

Figs.  6-10.     CYCLONEMINA  MITLTISTRIATA  n.  sp 672 

6.  Dorsal  view  of  type.    Sideling  Hill  Creek,  2~y2  miles  above  mouth, 

1700. 

7.  Enlargement  of  a  portion  of  the  surface  showing  ornamentation. 

X  5.    Same  locality. 

8.  Dorsal  view  of  a  shell  of  slightly  different  proportions.     Same 

locality. 

9.  Cast  of  interior.    Same  locality. 

10.  Internal  cast  of  a  very  large  shell.    Williams  Road,  Polish  Mountain, 
1600. 

Jennings  formation,  Parkhead  member. 

Figs.  11,  12.     TURBO  CORONOLA  n.  sp 673 

11.  Profile  from  a  replica.     The  original  cast  of  this  is  somewhat 

imperfect  or  distorted  about  the  lower  edge  of  the  aperture. 

12.  A  part  of  the  exterior  drawn  from  a  gutta-percha  squeeze. 

Jennings  formation,  Chemung  member,  National  Road,  6  miles 
west  of  Frostburg. 

Fig.  13.     TROCHONEMA  (GYRONEMA)  LIRATUM  (Hall) 674 

Dorsal  view.    Jennings  formation,  Chemung  member,  National  Road, 
east  of  Hancock,  2223. 

Figs.  14,  15.     MACROCHILINA  PULCHELLA  n.  sp 675 

14.  Internal  cast  of  the  only  specimen  observed.     X  5. 

15.  Exterior  of  the  same.    X  5. 

Jennings  formation.  Chemung  member,  Williams  Road,  Polish 
Mountain. 


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15 


12 


MOLLUSCA — GASTROPODA 


PLATE  LXIX 

PAGE 

Figs.  1,  2.     LOXONEMA  HAMILTONI,E  Hall 676 

1.  Dorsal  view  of  a  small  specimen.    X  2.    Western  Maryland  Railroad, 

2  miles  west  of  Pawpaw,  1597. 

2.  Dorsal  view  of  a  larger  individual  of  the  usual  proportions.     Same 

locality,  1485. 
Jennings  formation,  Parkhead  member. 

Figs.  3-7.     LOXONEMA  TEREBRUM  Hall 676 

3.  Dorsal  view  of  a  nearly  complete  example.    National  Road,  6  miles 

west  of  Frostburg. 

4.  Dorsal  view  of  a  small  shell.    Same  locality. 

5.  A  portion  of  the  exterior.    Same  locality. 

6.  Part  of  an  internal  cast.    Glade  Run. 

7.  External  and  internal  cast  of  a  specimen.     Same  locality. 

Jennings  formation,  Chemung  member. 

Figs.  8-10.    LOXONEMA  STYLIOLUM  Hall 676 

8.  9.  Dorsal  view  of  exteriors  of  shells  upon  which  ornamentation  is 

not  preserved. 

10.  Internal  cast  of  apical  portion. 

Jennings  formation,  Chemung  member,  Town  Creek,  2238. 

Figs.  11-14.     LOXONEMA  ( ?)  GLABRUM  n.  sp 677 

11.  Internal  cast.    Williams  Road,  Polish  Mountain,  1660. 

12.  Dorsal  view  of  exterior.    Same  locality. 

13.  Internal  cast.    Sideling  Hill  Creek,  2l/2  miles  above  mouth,  1700. 

14.  Dorsal  view  of  exterior  of  a  shell  probably  of  this  species.     Wil- 

liams Road,  Polish  Mountain. 

Jennings  formation,  Parkhead  member. 

Figs.  15,  16.     TRACHYODOMIA  PRECURSOR    (Clarke) 678 

Ventral  and  dorsal  views  of  shell.  X  1%.  This  is  a  barite  replacement 
of  the  fossil  from  the  Portage  formation,  Naples  beds,  Honeoye 
Lake,  New  York. 

Figs.  17,  18.     HOLOPEA  ROWEI  n.  sp 679 

17.  Internal  cast  of  a  large  specimen. 

18.  Dorsal  view. 

Jennings  formation,  Chemung  member,  Williams  Road,  Polish 
Mountain. 

Figs.  19,  20.     HOLOPEA  MARYLANDICA  n.  sp 680 

Dorsal  views  showing  variations  in  form.  Jennings  formation,  Che- 
mung member,  Williams  Road,  Polish  Mountain. 

Fig.  21.     HOLOPEA  HUMILIS  n.  sp 680 

Internal  cast  of  type.  Jennings  formation,  Parkhead  member,  2  miles 
north  of  mouth  of  Town  Creek,  1716. 


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10 


12 


15 


16 


19  20 

MOLLUSCA — GASTROPODA 


14 


21 


18 


PLATE  LXX 

PAGE 

Figs.  1-3.     PLATYCERAS  COMPKESSUM  n.  sp 683 

Three  views  of  type.    Jennings  formation,  Chemung  member,  west  of 
Green  Ridge,  near  Pennsylvania  line. 

Figs.  4-6.     ORTHONYCHIA  PROSSERI  n.  sp 681 

Three  views  of  internal  cast.    Jennings  formation,  Chemung  member, 
National  Road,  6  miles  west  of  Frostburg. 

Figs.  7-9.     ORTHONYCHIA  UNGUICTJLATA  n.  sp 682 

Three  views  of  type.    Jennings  formation,  Parkhead  member,  Williams 
Road,  Polish  Mountain,  1660. 

Figs.  10,  11.     ORTHONYCHIA  sp 682 

Enlargement  of  internal  cast.     X  2.     Jennings  formation,  Parkhead 
member,  Sideling  Hill  Creek,  2l/2  miles  above  mouth,  1700. 

Figs.  12-16.     PLATYCERAS  MARYLANDICUM  n.  sp 683 

12, 13.  Two  views  of  a  small  individual.    Parkhead  member,  Williams 

Road,  Polish  Mountain,  1660. 

14-16,  Three  views  of  type  specimen.    Chemung  member,  same  locality, 
2042. 
Jennings  formation. 

Figs.  17-19.     DIAPHOROSTOMA  LINEATUM  (Conrad) 684 

17, 18.  Two  views  of  same  shell. 

19.  Portion  of  surface  enlarged  X  7. 

Jennings  formation,  Chemung  member,  west  of  Green  Ridge, 
near  Pennsylvania  line. 

Figs.  20-23.     TENTACULITES  DESCISSUS  n.  sp 686 

20.  A  full  grown  example  showing  the  subequal  rings  of  early  growth 

and  the  alternation  in  size  in  later  stages.     X  2.     Green  Ridge, 
Allegany  County. 

21.  A  small  example.    Western  Maryland. 

22.  23.  Fragments  of  the  apical  parts  of  the  tubes  with  only  the  sub- 

equal  rings  present.     X  5. 

Jennings  formation,  Chemung  member,  Deer  Park. 

Fig.  24.     TENTACTTLITES  SPICTJLUS  Hall 687 

Shell  enlarged  X  5.     Jennings  formation,  Woodmont  member,  Ithaca 
fauna,  National  Road,  east  of  Millstone,  795. 


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MARYLAND  GEOLOGICAL  SURVEY 


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PLATE  LXXI 

PAGE 

Figs.  1-3.     STYLIOLINA  FISSURELLA  (Hall) 685 

1.  Surface  of  fragment  of  shale  covered  with  shells,  natural  size. 

2.  Fragment  enlarged.    X  3. 

3.  Single  individual.    X  6. 

Genesee  formation,  New  York. 

Figs.  4-6.     COLEOLUS  TENUICIXTUS  Hall 687 

4.  Cast  of  interior  of  shell  of  unusually  large  size.    Maryland-Pennsyl- 

vania state  line,  east  of  Ragged  Mountain. 

5.  6.  Apices  of  two  specimens.     X  6.    One-half  mile  north  of  Pawpaw. 

Jennings  formation,  Parkhead  member. 

Figs.  7-9.     HYOLITHES  ACLIS  Hall 688 

Three  views  of  cast  of  interior.  X  2.  Jennings  formation,  Parkhead 
member,  Sideling  Hill  Creek,  2l/2  miles  above  mouth,  1700. 

Fig.  10.     PHARETREIXA  TENEBROSA  Hall 690 

Specimen  showing  ornamentation.    Genesee  formation,  New  York. 

Fig.  11.     BACTRITES  ACICTJLUS  (Hall) 692 

A  specimen  showing  the  usual  crushed  and  incomplete  condition  of  the 
fossil.  Jennings  formation,  Genesee  member,  Williams  Road, 
near  Cumberland. 

Figs.  12,  13.     ORTHOCERAS  FILOSUM  Clarke 691 

Specimens  showing  the  surface  characteristics.  Jennings  formation, 
Woodmont  member,  Naples  fauna,  Town  Creek,  Gilpin. 

Figs.  14,  15.     ORTHOCERAS  DEMUM  Hall 691 

14.  Chamber  of  habitation. 

15.  A  part  of  shell  showing  septa. 

Jennings  formation,  Chemung  member,  National  Road,  east  of 
Hancock,  2223. 

Figs.  16-18.     ORTHOCERAS  CONSORTAI.E  Hall 690 

16.  Cast  of  a  portion  of  shell  showing  septa. 

17.  Portion  of  shell  showing  chamber  of  habitation. 

18.  Septum  showing  siphuncle. 

Jennings  formation,  Chemung  member,  Williams  Road,  Polish 
Mountain,  2043. 


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11 


16 


18 


MOLLUSCA — GASTROPODA  AND  CEPHALOPODA 


PLATE  LXXII 

PAGE 

Figs.  1-3.     MANTICOCERAS  PATERSONI  (Hall) 693 

1.  Shell  upon  which  sutures  are  not  preserved.     Chemung  member, 

Williams  Road,  Polish  Mountain,  2042. 

2.  Transverse  section  of  shell  shown  in  fig.  1. 

3.  Smaller  individual  preserving  suture  lines. 

Portage  formation,  Naples  fauna,  New  York. 

Figs.  4,  5.     PROBELOCERAS  LUTHERI  Clarke 695 

Two  small  specimens  neither  showing  septa,  tentatively  referred  to 
this  species.  Fig.  4X3;  fig.  5  natural  size.  Jennings  forma- 
tion, Genesee  member,  Wolfe  Mill,  Allegany  County. 

Fig.  6.     TORNOCERAS  UNIANGULARE  (Conrad) 696 

A  small  flattened  specimen  showing  the  characteristic  septal  sutures. 
X  2.  Jennings  formation,  Genesee  member,  Williams  Road, 
Cumberland. 

Fig.  7.     SANDBERGEROCERAS  CHEMUNGENSIS    (Vanuxem) 697 

Part  of  a  single  volution.  Jennings  formation,  near  base  of  Parkhead 
member,  White  Sulphur  Branch,  4  miles  southeast  of  Pratt. 

Figs.  8,  9.     PHACOPS  RAX  A   (Green) 699 

8.  Glabella.    Sideling  Hill  Creek,  2%  miles  above  mouth,  1700. 

9.  Pygidium.     Road  leading  northeast  from   Pratt,   %   mile  west  of 

15-mile  Creek. 
Jennings  formation,  Parkhead  member. 


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PLATE  LXXIII 

PAGE 

Figs.  1-3.     GLYPTASPIS  EASTMANI  n.  sp 700 

1.  Antero-ventro-lateral  plate  showing  surface  ornamentation.     Jen- 

nings formation,  base  of  Parkhead  member,  Horse  Ridge,  south- 
west of  Hancock,  1600. 

2.  Right  postero-ventro-lateral  plate  showing  surface  ornamentation. 

Jennings  formation,  Parkhead  member   (?),  west  of  Green 
Ridge,  near  Pennsylvania  line. 

3.  Fragment  of  an  undetermined  plate  from  the  same  locality  as  fig.  1. 


J53 


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